FactSageTM - Frequently Asked Questions - FAQ

(2023)
FactSage^TM is a thermochemical software and database package developed jointly between Thermfact/CRCT (Montreal, Canada) www.crct.polymtl.ca and GTT-Technologies (Aachen, Germany) www.gtt-technologies.de and is the result of over 30 years of collaborative efforts.     The FactSage web site is www.factsage.com.

FactSage 8.3 was released in 2023. For details on the programming and database changes click on What's New in FactSage 8.3

To contact us please send an e-mail to crct@polymtl.ca (Montreal, Canada) or info@gtt-technologies.de (Aachen, Germany).

The most recent version of FactSage - Frequently Asked Questions - FAQ is maintained on our website at www.factsage.com.

1. Introduction:

2. Data - Databases:

2.6 What is the purpose of the element database ELEM?
2.7 Can I see the parameters stored in the FACT and SGTE solution databases?
2.8 In the FACT compound database, why is Cp(T) data for Nd(g) specified over the small range 295-300 K?
2.9 How do Client PCs access the Server Compound and Solution databases? How are the Server and Client databases updated?
2.10 What are the thermodynamic properties of the electron gas, e[-](g)?

3. Windows Versions:

4. Installation Problems - Network Issues:

4.6 When I try and install a Client version and specify this path I get 'FactSage Network File Server not found'. What do I do?
4.7 My company has a site license. Can I install FactSage on my home computer? Can I take my laptop with me on trips?
4.8 Can I install both a client version and also a standalone version on the same PC?
4.9 Our company has several client PCs connected to the network. If I take the client PC home will it work with a dongle?
4.10 I have installed FactSage as a client (or standalone) but want to change it to a standalone (or client). What do I do?

5. Running - Passwords - Dongles:

6. Equilib and Phase Diagram Programs:

6.6 I am unable to include SO4 ion as a reactant in Equilib. How do I access the ions?
6.7 I keep seeing gaseous ions (or aqueous ions or organic molecules). How do I get rid of them?
6.8 How do I do plasma calculations? Are there data for gaseous ions?
6.9 How do I include organic molecules CxHy... for large values of x?
6.10 I have some questions on "Post-Calculation" in the List Window.

6.11 What is the purpose of the "include molar volumes" check box in the Menu Window?
6.12 For solid phases what is the difference between "S", "S1" and "S2"?
6.13 How can I fix an activity for a component in a slag system, for example a(CaO(liq)) in CaO-Al2O3-SiO2 (FToxid-SLAGA)?
6.14 How do I best calculate and plot the vapour pressure?
6.15 In Equilib can I mix mass units - for example 1 mole O2 + 2 grams FeS?

6.16 Can I export the results in the form of an Excel spreadsheet or graph?
6.17 When calculating the Ti-Al phase diagram why do I see odd looking phase boundaries for the TiAl and Ti3Al phases?
6.18 What is the purpose of the phase B2_BCC!BCC_A2 in the SGTE (SGTEsoln) solution database?
6.19 Where are the intermetallic compounds that are supposed to be part of the SGTE solution database?
6.20 Why is cementite a compound Fe3C in the compound database (SGTEbase) and a solution Fe-Cr-C in the solution database (SGTESoln)?

6.21 In Phase Diagram can I calculate and plot tie-lines?
6.22 In Phase Diagram can I calculate the equilibrium at any point on the diagram?
6.23 How can I stop the program from calculating?
6.24 In the Equilib output what does "the solution is unstable" mean?

7. Figure and Viewer Programs

8. Other Programs:

9. ChemSage Files:

10. Other Error Messages and Bugs:

1. Introduction

1.1 What is in the FactSage package? What are the leasing and purchase options?

FactSage^TM is a thermochemical software and database package developed jointly between Thermfact/CRCT (Montreal) and GTT-Technologies (Aachen) and is the result of over 30 years of collaborative efforts. FactSage can be downloaded from our websites and is available on a CD-ROM. FactSage is installed on a PC running under Windows XP, Vista, 7, 8, 10 and 11. The PC must have at least 1 GB free disk space.

• FactSage includes the following modules in a Windows environment:
  • Slide Show - slide show presentations of the modules including sample inputs - good for teaching and getting started
  • View Data - examine stored compound data (Cp(T), H, S, G, etc.) and list the solutions
  • Compound - enter pure substances data (Cp(T), H298, S298, etc.) in your private compound database
  • Solution - enter non-ideal mixing properties in your private solution database
  • Reaction - calculate the thermochemical properties of a species or chemical reaction
  • Predom - calculate and plot isothermal 1-, 2- and 3-metal predominance area diagrams using compound databases
  • EpH - calculate and plot 1-, 2- and 3-metal Eph (Pourbaix) diagrams using compound databases
  • Equilib - Gibbs energy minimization module featuring ChemSage for treating complex heterogeneous equilibrium using compound and solution databases - our most popular program
  • Phase Diagram - calculate and plot phase diagrams using compound and solution databases - also very popular
  • OptiSage - optimization of thermodynamic and phase diagram data
  • Results - graphics program for treating Equilib Results files
  • Mixture - edit mixtures and streams for input to Equilib
  • Figure - manipulate, edit and plot figure and phase diagrams already calculated by FactSage
  • Fact-XML - customize and plot Equilib results
  • Viscosity - calculate viscosities of glasses and melts
• Normally the FactSage package includes either the FACT or SGTE compound and solution databases (you can get both if you want) with maintenance, support and updates to programs and databases.
• FactSage may be installed on a server for use at the site, or on a limited number of PCs for individuals.
• Site licenses enable FactSage to be used by all personnel at a geographical site.
• Special academic rates are available.

For information on leasing or purchasing and a list of our representatives go to www.factsage.com.

FactSage is a thermochemical software and database package that runs under Microsoft Windows.

Minimum System Requirements: Equivalent to the minimum system requirements for running Microsoft Windows 10 operating system.

Recommended System Requirements: Operating System: Microsoft Windows 10 or above; CPU: Intel Core i7 2.8 GHz (or an equivalent AMD processor) or better: RAM: 16 GB or more: Storage: 7200 RPM or better HDD or SSD.

FactSage can be installed as a 1. Standalone, 2. Network File Server or 3. Network Client version on a local hard disk on the PC.

• Standalone means one version of FactSage on the PC. The program can not be accessed by other PCs. The Standalone PC requires a security key (dongle) attached to the USB or printer port. You will still be able to run the printer.

• Network File Server means one public version of FactSage on the PC. The files can be read and copied by other PCs (Network Clients) but there will be no write operations to the server. The server directory is 'share read-only'. The Network File Server PC requires a computer password.

• Network Client means that the PC is accessing FactSage files already installed on another PC (Network File Server). The Network Client does not require a password or a dongle - only the Network File Server requires a password.

For the most recent detailed information including screenshots of the various stages go to www.factsage.com and click on 'Installation Instructions'.

These can be arranged.

It is possible for workshop participants to download and install the FactSage Workshop package prior to the workshop.

More information is given at FactSageWS_Info

FactSage^TM is a thermochemical software and database package developed jointly between Thermfact/CRCT (Montreal) and GTT-Technologies (Aachen) and is the result of over 30 years of collaborative efforts. It is the fusion of two well-known software packages in the field of computational thermochemistry: FACT-Win (formerly FACT) and ChemSage (formerly SOLGASMIX). It consists of a series of modules that access and manipulate thermodynamic databases and perform various calculations. Some of the FactSage modules (Equilib, Phase Diagram, OptiSage) employ the Gibbs energy minimizer of ChemSage.

Thermfact Ltd. holds copyright and exclusive ownership of the following products:

• FactSage Main Menu program and SageTest security module.
• View Data, Compound, Solution, Reaction, EpH, Predom, Results, Mixture, Figure, Viewer programs, user interfaces and associated data search engines.
• Equilib, Phase Diagram and OptiSage user interfaces, graphics and associated data search engines.
• Fact-Xml program, Trans-Xml translation module, and XML language protocol.
• FactSage Browser navigation tool for database documentation.
• FactVisc program and associated database for viscosities of liquid oxides.
• FACT compound and solution databases - FactPS, FTfrtz, FThall, FThelg, FTmisc, FTnucl, FTOxCN, FToxid, FTpulp, FTsalt.

GTT Technologies holds copyright and exclusive ownership of the following products:

• Equilib, Phase Diagram and OptiSage engines.
• ChemApp programmable object code used for the development of user-defined applications.
• SimuSage process simulation package.
• ChemSheet, CSFAP, FactSage-TEACH and KilnSimu.

For the latest news about FactSage 8.3 including known 'bugs' go to www.factsage.com and click on 'FactSage 8.3 ~ News ~'

Unless the bug is very serious we do not send out updates. In most cases we suggest a way to handle or avoid the bug.

1.6 What's new in FactSage 8.3

For details on the programming changes in FactSage please click on What's New in FactSage 8.3

1.7 When is the release date of the next version of FactSage?

Typically a new version of FactSage is released each year but this may vary depending upon the amount of changes. For example FactSage 8.3 contains important changes and has been released after a period of 1 year. The number of files in FactSage 8.3 is over 17 000.

1.8 Do you have a demonstration version of FactSage?

Yes we do. There are two optioms.

FactSage Education (FactSageEdu) is a free demonstration version of FactSage that may be downloaded from www.factsage.com. It contains all the slide shows, documents, phase diagrams etc. that are stored in the full FactSage Packahge but it does not require a dongle. Its main restriction is that calculations are limited to 3 elements.

It is ideally suited for teaching thermochemistry in universities. It also serves as a demonstration package for those interested in finding out more about FactSage.

For more details visit FactSageEdu.

Fact-Web is an internet programs offer free but limited access to the FactSage thermochemical software and FACT compound databases.

For more details visit Fact-Web.

2. Data - Databases

2.1 What databases are currently available in FactSage?

For a summary of databases click on database summary.

Complete details on the databases are available by clicking on 'Documentation' button in the FactSage main menu. Alternatively go to www.factsage.com and click on 'Documentation'.

In FactSage there are two types of thermochemical databases - compound (i.e. pure substances) and solution databases.

Compound data are for stoichiometric solid, liquid and gaseous species such as SiO₂(s), FeS(liq), SO₂(g). Allotropes (for example graphite C(s1) and diamond C(s2)) and isomers (for example ethylene C₂H₄O(liq1) and acetylene C₂H₄O (liq2)) may be included. Data on a few non-stoichiometric compounds such as FeO_x (x = 0.947) are also stored. Depending on the type of phase (solid, liquid, gas) and data availability, the stored properties include Delta H(formation, 298.15K, 1bar), S(298.15K, 1bar), Cp(T), magnetic coefficients (Curie or Neel Temperature and magnetic moment), molar volumes (298.15K, 1bar) coupled with expansivities and compressibilities as functions of T. Dilute aqueous solution data (Henrian activity coefficients) and non-ideal gas properties (using T_crit., P_crit., V_crit., the acentric factor (omega) and the dipole moment) are also stored in the compound databases.

Solution data are for solid and liquid alloys, concentrated aqueous solutions, ceramics, salts, mattes, slags etc. The data are stored in the form of Gibbs energy functions for the phase constituents and parameters for the excess Gibbs energy of mixing between the phase constituents. FactSage supports 14 different solution models including simple polynomial models such as the Redlich-Kister or the Legendre polynomial combined with different higher order extrapolations (Muggianu, Kohler, Toop), the quasichemical model, Pitzer parameters and sublattice models. Additional solution models are planned.

With the FactSage package you would normally get either the FACT⁺ or SGTE⁺⁺ databases - as you wish. You can also obtain both databases (for an additional cost).

There are other databases available (for an additional cost) - these are all listed in the 'Documentation' section.

You can also create your own private databases using the Compound and Solution programs. With the OptiSage program you can utilize experimental phase diagram and thermodynamic data in order to obtain the coefficients of G-functions of compounds or of the constituents of solid and liquid solution phases as well as the coefficients of excess Gibbs energy models for the solutions.

Furthermore, if you are a ChemSage user, you can convert ChemSage data files into FactSage compatible databases - see the section on ChemSage Files.

For dilute solutions there are several hundred aqueous species stored in the FACT compound database. For concentrated solutions there are Pitzer parameters for over 200 species stored in the FACT solution database (FTmisc-PITZ).

The FACT Helgeson database, FThelg, contains infinite dilution properties for over 1400 aqueous solute species taken from the GEOPIG-SUPCRT Helgeson public database and include the Helgeson equation of state for temperatures up to 350ºC and pressures up to 165 bar. The data are stored as 3 aqueous solutions FThelg-AQID, -AQDH, -AQDD.

• FThelg-AQID assumes an ideal dilute solution and is generally valid up to approx. 0.001 molal.

• FThelg-AQDH incorporates the Debye-Huckel equation, and is generally valid up to approximately 0.02 molal.

• FThelg-AQDD incorporates the extended Debye-Huckel (Davies) equation and is generally valid up to 0.5 molal.

Yes you can. You can include other databases as well - for example private data imported from a ChemSage file.

In most cases you would be using the Equilib and Phase Diagram programs where there is provision to ignore duplicate compounds. For example you could request the program to always use say FACT compound data and only use SGTE compound data if FACT data are not available, or vice versa.

On the other hand the solution databases are very different. FACT data are mainly for non-alloy systems (slags, mattes, ceramics) whereas SGTE data are for alloys. You could do calculations using say the FACT slag, ceramic and matte data with say the SGTE solid and liquid alloy solutions. Note that you must always use the SGTE compound database (for intermetallic compounds) together with the SGTE solution database since alloy systems contain both stoichiometric compounds and solutions.

Complete details on the databases are available by clicking on 'Documentation' button in the FactSage main menu. For a presentation of the FACT, FactSage and SGTE databases that are FactSage compatible click on FactSage - Summary of Databases.

Yes if you are interested in a combination of phases that are mutually exclusively stored in the FACT and the SGTE databases. This holds for example for calculations of corrosion of alloys. The alloy phase data are stored in the SGPS and SGTE databases whereas the possible corrosion products (oxides or salt) are contained in the FactPS, FToxid and FTsalt databases.

If you are using any public database there is no need to select the ELEM element database.

But for a private (user-defined) database you may need to have access to elemental data. The ELEM database provides the necessary standard state information on the elements - the data in ELEM are taken from the FACT and SGTE compound databases (FactPS and SGPS).

The parameters stored in these databases are protected and cannot be inspected by the programs.

The reported data for Nd(g) includes a constant value for Cp at 298.15 K. Since Cp values are temperature dependent, this implies the Cp data will be imprecise at other temperatures. Nevertheless it will remain fairly constant over a few degrees and we have applied a conservative range of 5 K. Outside this temperature range in Equilib, for example, the species will be flagged with a 'T'.

When a Client PC first runs FactSage all databases and support files on the Server (i.e. all files of the type .sln, .sdc, .cdb, .crf, .htm and .txt) are copied or updated in the FactData directory of the Client PC (typically c:\FactSage\FactData). Any changes made to the Server databases will be automatically made to the Client PC databases the next time the Client PC runs FactSage.

These values are hard coded into the modules:

e[-](g): mol. wt. = 0.00054876, DH(298K) = 0, S(298K)= 4.988 cal/mol, Cp (const) = 4.968 cal/mol-K

3.1 Does FactSage run under Windows XP? Vista? 7? 8? 10? 11? Which Windows version is best?

FactSage will run under Windows XP, Vista, 7, 8, 10 and 11. You need a computer with at least 1 GB free disk space. We find there is little difference in performance between the various versions of Windows.

The best way to improve the performance is increase the computer speed and RAM.

4. Installation Problems - Network Issues

4.1 I am the network manager and I can not figure out how to install FactSage on the client PC. Any ideas?

On the FactSage CD-Rom consult the file ShowMe.htm. It explains in detail

Installing FactSage on the PC

Installing FactSage as a Standalone PC

Installing FactSage as a Network Server PC

Installing FactSage as a Network Client PC

For the most recent detailed information including screenshots of the various stages go to www.factsage.com and click on 'Installation Instructions'.

The server acts as a read-only file server. When FactSage is run on the client PC the necessary files are copied from the server and loaded into the memory of the client PC. The client PC does all the calculations and i/o - there are no write operations to the Server disks.

This is a common situation with work stations where paths start with \\. You may want to ask your Network Manager to show you how to specify on your PC a network path with a letter (for example p:\) that is equivalent to your server path. For example open 'Explore' (by clicking on Start with the mouse right button) then 'Explore > Tools > Map Network Drive ...' etc.

For the most recent detailed information including screenshots of the various stages go to www.factsage.com and click on 'Installation Instructions'.

Let us say on the network the public server path is 'p:\FactSage'. That is, the installation program will look for 'FactSage.exe' in the directory 'p:\FactSage' (ie the installation program is hunting for 'p:\FactSage\FactSage.exe'). If your map drive points to '\FactSage' then the PC will not see the full name. Try 'p:\' (ie installation program is hunting for 'p:\FactSage.exe').

For the most recent detailed information including screenshots of the various stages go to www.factsage.com and click on 'Installation Instructions'.

Many companies have a site license where there is file server installation together with one or two dongles for standalone installations. Additional dongles may be purchased.

You are permitted to take the company dongle home in order for you to do company business at home on your PC or laptop. You are permitted to visit another site or company or go to a conference or meeting and take along your laptop with the company dongle in order to show your company business. However, you are not permitted to install FactSage on a PC at a second site and use the company dongle - in this case a second site license is required.

Yes but not in the same directory. The problem is that the two installations are very different. The client installation stores few files on the PC since it accesses those stored on the file server, and the server has a password that authorizes the client. The standalone version stores all the files on the PC and uses a dongle for authorization.

If you wish to connect your laptop to the network during the day (client installation) and then take it home in the evening (standalone installation) you need to install FactSage as both a client and as a standalone version on the same PC. This is one way on how it could be done:

• Install the client version in the usual way - use the default directory (c:\Factsage). Make sure it runs OK. Edit and rename the FactSage short-cut (the 'F') that appears on the screen (click on the short-cut with the mouse right button - rename 'FactSage' to say 'FactSage LAN'). If you do not rename the short cut it will be overwritten when you install the standalone version.
• Install the standalone version in the usual way - specify a different directory say 'c:\FactHome' (remember no more than 8 letters per directory name - e.g. 'FactSageHome' is to long). Make sure it runs OK. Edit its FactSage short-cut and rename 'FactSage' to say 'FactSage Home'.

You will be able to access the same private files and databases stored on the PC.

No - you need to install FactSage as both a client and as a standalone version on the same PC. Please refer to the previous question.

There are two safe ways to convert a client version to a standalone (or vice versa):

• Install the two versions of FactSage in two different directories. Please refer to the previous questions.

  or

• First completely uninstall FactSage from the PC - in the FactSage Menu Window click on 'Tools > Remove/Uninstall FactSage ...' and follow the instructions. When done you must then delete the FactSage folder (c:\FactSage) - this is important since it removes pointer files that may confuse the new installation. Now install FactSage in the usual manner.

5. Running - Passwords - Dongles

5.1 I have attached a MemoHASP security key (dongle) but I keep getting FactSage-Setup. What's wrong?

If this is a Network Server installation, then to activate the Network Client PCs the Network Server requires a password. FactSage Client installations do not recognize this type of dongle.

For a Standalone version there is a feature that was introduced in FactSage 7.0 and displays the status of the FactSage dongle attached to the computer. This helps you to determine which factor is the source of the problem.

- Run FactSage 8.3 and display the FactSage Main Menu Window.

- Click on 'Tools > FactSage dongle status > Explanation of dongle status... ' and follow the instructions.

6. Equilib and Phase Diagram Programs

6.1 What is the meaning of "T" ("X", "C") for certain species in the Equilib Results Window?

The "T" indicates the data for that species were extrapolated out of the reported Cp range T(min) - T(max). Cp ranges are given in the List Window (or if you point to a calculated species in the Equilib Results Window and double-click, Compound will list its data).

• If T < T(min), the Cp expression is extrapolated.
• If T > T(max), the Cp value at T(max) is kept constant above T(max).

If the species is a stable product and has been extrapolated several hundred degrees above its reported Cp range then one may wish to question the validity of the calculation. In this event the Compound program may be used to enter your own data.

The "X" refers to allotropes and in most cases it is not important. Where data are missing, we do not permit allotropes to extrapolate into each others Cp ranges. This is because many allotropes tend to extrapolate poorly which is quite significant since the Gibbs energy between allotropes (the basis for selecting that which is most stable) may be quite small.

The "C" appears when the calculated composition of a species in a real-solution is outside its recommended composition range. For example, in a liquid steel (FTmisc-FELQ) containing oxygen, a calculated oxygen content of 20 wt.% O is clearly too high and would generate a "C" flag since this is above the recommended limit. The recommended composition ranges of the solutions are given in the List Window.

FToxid-SLAGA, FToxid-SLAGB, FToxid-SLAGC etc. are all liquid oxide solutions from the FACT FToxide database but for different combinations of components. For example, most calculations with FToxid-SLAG use FToxid-SLAGA - this is the slag solution with all the oxides and includes up to 10% sulfur if this element is also included in the calculation.

More extensive details on the FToxid-SLAGA, -SLAGB, etc. phases can be found in the Documentation located in the FactSage Main Menu - click on '[FToxid] - FACT oxide database > - description of solutions'.

Summary of FToxid slag phases:

[FToxid-SLAGA] A-Slag-liq Oxide liquid/glass with S

Oxides of: Al, As, B, Ca, Co, Cr(II), Cr(III), Cu(I), Fe(II), Fe(III), Ge, K, Mg, Mn(II), Mn(III), Na, Ni, Pb, Si, Sn, Ti(III), Ti(IV), Zn, Zr + (S in dilute solution (<10%))

[FToxid-SLAGB] B-Slag-liq Oxide liquid/glass containing sulfate

Oxides of: Al,As,B,Ca,Fe(III),K,Mg,Mn(II),Na,Ni,Pb,Si,Ti(III),Ti(IV),Zn,Zr + SO4 in dilute solution (< 10 weight %)

[FToxid-SLAGC] C-Slag-liq Oxide liquid/glass containing phosphate

FToxid-SLAGC was removed in FactSage 7.0. The solubility of P2O5 in oxide liquid/glass is more accurately described by SLAGA.

[FToxid-SLAGD] D-Slag-liq Oxide liquid/glass containing carbonate

Oxides of: Al,As,B,Ca,K,Mg,Na,Si,Ti(III),Ti(IV),Zr + CO3 in solution (< 40 weight %)

ontaining water/hydroxide

[FToxid-SLAGE] E-Slag-liq Oxide liquid/glass containing water/hydroxide

Oxides of: Al,As,B,Ca,Fe(II),Fe(III),K,Mg,Mn(II),Na,Si,Ti(III),Ti(IV),Zn,Zr + OH/H2O in dilute solution (< 10 weight %)

[FToxid-SLAGF] F-Slag-liq Oxide liquid/glass containing iodide

Oxides of: Al,As,B,Ca,Fe(II),K,Mg,Mn(II),Na,Si,Ti(III),Ti(IV),Zr + I in dilute solution (< 10 weight %)

[FToxid-SLAGG] G-Slag-liq Oxide liquid/glass containing carbide, nitride and cyanide

FToxid-SLAGG was removed in FactSage 6.4. For calculations of solubilities of C and N in oxide melts, use the FTOxCN database.

[FToxid-SLAGH] H-Slag-liq Oxide liquid/glass containing fluoride and chloride

Oxides of: Al,As,B,Ca,Co,Cr(II),Cr(III),Cu(I),Fe(II),Fe(III),Ge,K,Mg,Mn(II),Na,Ni,Pb,Si,Sn,Ti(III),Ti(IV),Zn,Zr + (F, Cl in dilute solution (<10%))

[FToxid-SLAG?] ?-SLAG-liq Oxide liquid/glass

All species - use with caution. Because of the complexity of the models involved, the use of FToxid-SLAG? is not encouraged. Unless you carefully follow the instructions about removing certain components from the component list, completely erroneous calculations can result.

This is important! Any solution phase with a "?" has not been fully assessed thermodynamically. It may even be possible that certain combinations of constituents are not permitted (see below)! These "?"-type solutions are provided for the convenience of certain expert users who wish to perform special calculations. These solutions should not be selected as possible product phases unless you really know what you are doing (for example selecting "FToxid-SLAG?" often causes the program to crash - see below for why this happens). Please use an approved subsystem instead (FTsalt-SALTA, FToxid-SLAGB, etc..).

It is possible to select only certain components of a solution. For example, were you to remove the "+" in the column beside the component MnO in FToxid-SLAGA by clicking on it, then the calculation would assume that MnO is insoluble in the slag. However, it is strongly recommended that you always choose all the components in a solution (except in the case of "FToxid-SLAG?" - see below). Suppression of some components can result in logical inconsistencies with grave consequences.

For those who nevertheless insist on doing this, the following special rules should be noted:

(1) In a salt phase (like Li, Na, K/F, Cl, Br), every possible pair of anions and cations must be chosen. For example, you can choose the subsets (LiCl, KCl, LiF, KF) or (LiCl, KCl), but you can't choose (LiCl, KCl, LiF). This rule applies also more generally to any solution with 2 sublattices.

(2) In "FToxid-SLAG?", if a non-oxide component such as MgS or MgCO₃, is chosen, then its corresponding oxide (MgO) must also be chosen.

(3) In "FToxid-SLAG?", if a group of non-oxide components is chosen, then all combinations of anions and cations within the group must be chosen. This is like rule (1) above. For example, you cannot select MgS, Na₂S, NaCl without also selecting MgCl₂.

(4) WARNING: In certain cases the use of "FToxid-SLAG?" can cause erroneous results, or a crash, unless you remove certain components from the species selection. For example MgS, CaS and CaCO₃ are all components of "FToxid-SLAG?", but MgCO₃ is not. Suppose that your reactants include Mg, Ca, S, C and O, and you select "FToxid-SLAG?" then MgS, CaS and CaCO₃ will appear in the list of components of "FToxid-SLAG?" but MgCO₃ will not be present. Therefore, in order to respect the rule that all combinations of anions and cations within a group must be selected, you must remove either CaCO₃ or MgS from your selected components of "FToxid-SLAG?".

Selecting "FToxid-SLAG?" often causes the program to hang up or crash - see the previous question on why this happens.

The solution dataset "FToxid-SLAG" uses the QuasiChemical Model (developed at the CRCT) to treat the thermodynamic properties of this complex liquid / glass oxide that may contain Al, As, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Ti, Zn, Zr components with dilute amounts of S, SO₄, PO₄, H₂O/OH, CO₃, F, Cl and I. The scientific community recognizes that the QuasiChemical Model is the best for treating this type of ionic system, however the complexity of the model slows down the calculation of the equilibrium products especially if FToxid-SLAG contains non-oxide constituents (S, SO₄, PO₄, H₂O/OH, CO₃, F, Cl, I) - the presence of S may increase the computational time by an order of magnitude or more in large systems!

In Equilib if you point to the Species heading in the Reactants Window, click with the mouse right button and then select 'Help', you will see that charged ionic species can not be used as reactants in Equilib. This assures the system maintains electroneutrality. (We may change this option in the future.)

To include ionic species in the database search please refer to the next question.

Click on the "Data Search" menu bar in the Reactants Window. Gaseous ions, aqueous species and large organic molecules may be included or excluded in the data search. These options are included in order to reduce the total number of undesired species in system. The maximum number of carbon atoms, x, for organic species CxHy… in the database search can be set from 2 to 10 (the recommended setting is x = 2).

Please refer to the previous question, 6.7. The default settings on installation of FactSage are such that gaseous ions are NOT included in the search of the databases. So you must actively include them by selecting gaseous ions after clicking the "Data Search" menu bar. Once you have made this choice it becomes the new default.

Please refer to the earlier question, 6.7. The default settings on installation of FactSage are such that organic molecules CxHy.. where x > 2 are NOT included in the search of the databases. You can change the value of x by clicking the "Data Search > Limit Organic Species, CxHy ..." menu bar.

Why do the activities of certain species in the List and Selection Windows appear in italics?

The activities of these species have been post-calculated. The respective species have not been included in the actual equilibrium calculation. If you have not used the ‘Predominant’ feature in your calculation you should check for activities that are greater than one. If you find such cases you should custom select the respective species and repeat the calculations. Otherwise your calculated equilibria are for metastable states.

What is post-calculation?

The activities of the compound species in equilibrium with the computed products are calculated. The mass balance is not taken into account. In ChemSage these would be called dormant species. Post-calculated activities always appear in italics.

Why are the solutions not included in the post-calculations?

We have a theoretical solution ready and we hope to realize the programming one day.

Sometimes the activity of some components reaches values above unity (1.0) during post calculations. How is this possible?

Because they are not included in the mass balance. Hence if you include these species as possible products then one or more of them will be a stable product. If you do NOT include them you must keep in mind that your computed equilibria are for metastable states!

This option applies to condensed phases (pure solid and liquid compounds, and real solutions) and is only meaningful at very high pressures. For normal calculations it is recommended that you leave this box unchecked. When the "include molar volumes" box is checked, all solid and liquid phase molar volume data (including compressibility and expansivity data when available) will be employed in the VdP term. For such calculations it is recommended that you also select the "real gas" option in the Menu Window.

Important note: if a species has no volume data, its molar volume is assumed to be zero and the calculation of the VdP term will be in error! This may cause unpredictable results at high pressures as it will tend to stabilize species with small (or zero in this case) molar volumes. Such species will be flagged with a " o " in the Results Window.

These are allotropes. Copper has only one allotrope, s or s1. Carbon has two allotropes: graphite(s1) and diamond(s2). In Reaction, Predom, EpH and Equilib to list the phases and other data simply point to a compound species and 'double-click' - View Data will display its compound data (this even works in the Equilib Results Window).

Go to the Equilib Menu Window. In the "compound species" frame click on "liquids" with the mouse right button. Now you can custom select the species. For example to include CaO(liq) in the calculation you click on its "+" column. For the extended menu click the mouse right button and go down the menu to "activity > .... " etc. If the calculation is successful you will see that a certain quantity CaO is added to (or removed from) the system. Thermodynamically this type of calculation is called an "open system" calculation, i.e. the "input amount" of the substance is the result of the calculation.

If the substance vaporizes to form a single gaseous species of the same composition then you can use the Reaction module. Simply enter the reaction, for example H₂O(liq) = H₂O(gas), and select isothermal calculations. The calculated equilibrium constant is equal to the vapour pressure.

Use Equilib for real systems possibly involving dissociation (CaCO₃) or polymerization (Na). In the Reactants Window enter your initial substance, e.g. CaCO₃ or Na. Then in the Menu Window set the temperature range (e.g 500 1200 100), leave the pressure box undefined (blank), fix a constant volume 'Product V' (small enough that some condensed substance remains - say 1.0), and then click the calculate button. For the gas phase that is formed the total pressure is given. That is the pressure that can also be measured experimentally (for example in a torsion Knudsen effusion apparatus). Furthermore the partial pressures of the possible gas species are given thus simulating a mass spectrometric analysis of the molecular beam that emanates from a Knudsen cell.

To plot the total pressure as a function of temperature in the Results Window click on 'Output > Plot > Axes > P vs T ...'. To plot the partial pressure of a species as a function of temperature click on 'Output > Plot > Axes > activity vs T ...' and then click on 'Select' and identify the species to be plotted. .

In the Reactant Window you override the input default mass units by entering ' mol' and ' g' following the amounts in the Mass input box. For example

• Default units:
        1       O2
  +    2       FeS
  +    3       PbS
  
• Mixed units:
        1  mol    O2
  +    2 g        FeS
  +    3           PbS
  

The mass unit for PbS is the default value.

To override the output mass units click on the Parameters drop-down menu in the Menu Window.

In the Equilib Results Window click on "Output > Save as .. .". This enables you to manipulate and export the results in the form of text files, spreadsheets and much more. For example you can create spreadsheets of f(y) where y = T, P, V, H, S, G, U , A or species mole, gram, activity, mass fraction and f = y, log(y), ln(y), exp(y) etc. for Lotus 1-2-3, Microsoft Word, Excel.

In the Equilib Results Window click on "Output > Equilib Results file > Plot results ... etc". You can create results files (*.RES) that can be manipulated by program Results to produce graphs.

TiAl and Ti₃Al (as well as many other phases in the SGTE Solution database) have been treated with a two sublattice model that takes care of the atomic long range ordering of these phases. The phase constituents of TiAl for example are Ti₁Al₁, Ti₁Ti₁, Al₁Ti₁ and Al₁Al₁ or written in an overall formula (Ti,Al)₁(Ti,Al)₁. This means that both kinds of atoms can occupy both sites. However, there is actually a preference in site occupation such that one sublattice is mainly occupied by Ti and the other mainly by Al. Which element occupies which site is decided by the lowest Gibbs free energy of the phase. This lowest Gibbs free energy can only be found properly if TWO copies of the phase are used in the calculations, i.e. if the I-option (Immiscibility) is set for that phase.

When two copies (i.e. I-Option) of TiAl and of Ti₃Al are used in the phase diagram calculation the phase boundaries corresponding to the lowest Gibbs free energies of the respective phases are found and no odd looking extrapolations are observed.

In general it is advisable to inspect the list of phase constituents for "intermetallic" phases since several of these have been treated along the lines of TiAl above. Whenever phase constituents are shown that contain the same elementary components on two or more sublattices then the I-Option must be used for that phase in order to obtain the proper phase equilibria. This also applies for calculations with the Equilib program.

For the body centered cubic structure (BCC) there is a disordered state in which atoms randomly occupy the sites, and there is an ordered state with preferential occupation of the sites. For the Fe-Al (and Fe-Si) system the transition of the disordered (Fe-rich) state into the ordered state at high Al- (and Si-) content has been modelled such that the Gibbs free energy of the disordered state (BCC_A2) is taken as the basis of the calculation and the ordering energy for B2_BCC is added as an extra but necessary contribution. Such a case is denoted by the by the full name B2_BCC!BCC_A2.

This means that whenever B2_BCC is selected for a calculation, BCC_A2 is also selected automatically by the program (but not vice versa). Since B2_BCC is ordered, the minimum Gibbs free energy must be calculated in order to find the correct distribution of elements on the sites, and so the I-option must be used for this phase. See also the previous question on TiAl.

In FactSage the SGTE Solution database is split into two parts:

• SGTE2022base is the compound database and contains the intermetallic compounds with fixed stoichiometry
• SGTE2022soln is the solution database and contains all the other phases

In order to include all species in Equilib and Phase Diagram, make sure you always select both SGTE compound and solution databases - in the Reactants Window click on 'Data Search > Databases ...'.

Some of the compounds in the SGTE database such as Fe₃C cementite are actually end members (phase constituents) of higher order solution phases. Thus in Fe-Cr-C (and higher order systems) the cementite phase is found in the list of solution phases. For Fe-Cr-C the constituents of cementite are Fe₃C₁ and Cr₃C₁. Both of these are metastable in the respective binary subsystems and the cementite phase is only found as a stable phase when both Cr and Fe are present in the system.

However, the degree of metastability of Fe₃C₁ with respect to Fe and C is much less than that of Cr₃C₁ with respect to Cr and C. Thus it is possible to find under certain conditions cementite in the Fe-C system but not in the Cr-C system. In order to facilitate appropriate equilibrium and phase diagram calculations for the respective binary subsystems, Fe₃C (and other compounds) have been included separately as stoichiometric compounds in SGTEbase while Cr₃C is only contained in the cementite solution phase that is stored in SGTEsoln.

In the Phase Diagram Menu Window click on the 'Parameters' drop-down menu and you are presented with the Parameters Window. Make sure the 'show tie-lines' box has been checked. After the diagram has been plotted, in the Figure Window point with the mouse and you will see the calculated 2-phase tie-line at these coordinates. To plot the tie-line first select the 'tie-lines mode' (see the button on the left hand side in the Figure Window), then point and click.

After the diagram has been plotted, in the Figure Window first select the 'phase equilibrium mode' (see the button on the left hand side in the Figure Window) and then point and click and you will see the calculated equilibrium at these coordinates. The format is identical to that of the Results Window of Equilib. You can calculate as many points as you wish. When you return to the Phase Diagram Main Menu you can then go to the Results Window and manipulate all the results.

In the Menu Window click on the 'Parameters' drop-down menu and you are presented with the Parameters Window. Make sure the 'stop/kill yes' box has been checked. During the calculation you will see a window that gives you the options to stop or kill the application. If this does not work then in the FactSage Main Menu click on 'Tools > Reset programs ... ' and follow the instructions on how to terminate a program.

This message may appear in the Results Window when the program is having difficulty finding a solution. It means that all convergence tests have not been satisfied. However the output should be correct.

7. Figure and View Figure Programs

7.1 Why are there two programs that display figures - Viewer and Figure?

Viewer is a simple and more efficient version of Figure for drawing figures calculated by FactSage. With Viewer several figures may be viewed at the same time with little drain on the Windows resources.

Figure permits editing figures as well as manipulating the results of Equilib and Phase Diagram. It uses extensive Windows resources and may pose a drain on small computers. The high-quality diagram is suitable for reproduction and publication. It is primarily used for figures produced by Phase Diagram.

8. Other Programs

8.1 In Predom where is the C(graphite) field and the wustite solid solution Fe_xO for the diagram Fe-a(C)-P(O2)?

Predom generates classical predominance area diagrams, in the case of Fe-C-O a diagram that shows which oxide and carbide compounds of Fe are stable - hence C(graphite) is missing. Predom only makes use of species from a compound database. Solutions, such as wustite, are not incorporated in the calculations.

It is advisable to use the new module Phase Diagram. This module handles all condensed phases in a system, no matter whether they are compounds such as C(graphite) or solutions such as the wustite phase.

The Pourbaix diagram is calculated using thermodynamic data from the pure substances (compound) database and assuming all solutes are Henrian with respect to H₂O(liq) the activity of which is set to 1. This is why all the lines are straight and the resulting (ideal) diagram is simple but only an approximation to the true system. In principle one could calculate the diagram say from pH = -5 to 20. It would be thermodynamically correct (within the constraints of constant Henrian activity coefficients and unit water activity) but clearly unrealistic.

We choose -2 to 16 as default values (which you can change to any values) because M. Pourbaix used these values in the "Atlas of Electrochemical Equilibria in Aqueous Solution", Pergammon Press, 1966.

For realistic calculations of concentrated aqueous solutions one should use program Equilib and the Pitzer parameters in solution FTmisc-PITZ.

For some systems, for example the one-metal Fe-SO2(g)-O2(g) system with compound data, the diagrams are the same. In Predom a two- (three-) metal system always generates domains that have 2 (3) species. In Phase Diagram, if you select a composition variable that lies on a stoichiometric compound line then one of the species in a two- or three-metal system may not appear on the figure since it has zero moles. If you calculate the equilibrium within such a domain (figure 'phase equilibrium mode') then you will see the missing species has 0 moles but unit activity.

There are fundamental differences between the programs. Predom can only access the compound databases.

Unlike Phase Diagram, Predom offers some options useful in predominance-type diagrams. These include

• simple input tailor-made for predominance area diagrams
• list of invariant points
• total pressure isobar
• provision to set activities to a common value

On the other hand Phase Diagram offers some powerful features, including:

• access to both the compound and solution databases
• diagrams accessible to the Figure program
• provision to create readily a temperature predominance diagram
• more than 4 components

Fact-XML is an add-on to the Equilib program. After calculating an Equilib equilibrium, in the Results Window click on the 'XML' icon to an *.XML file and run Fact-XML.

Extensible Markup Language (XML) is a simple, flexible text format derived from SGML (ISO 8879). Originally designed to meet the challenges of large-scale electronic publishing, XML is playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere. The Fact-XML format used in Equilib was inspired by the MatML extensible markup language developed by NIST (U.S.) for the interchange of materials information. Storing the data in XML enables you to access, manipulate and plot all the Equilib derived information, much of which is not accessible in the FACT and ChemSage output formats. Since XML files can also be read through Excel software, you can manipulate the data as you wish. XML files are Internet friendly and can be accessed in a browser environment.

9. ChemSage Files

9.1 I am a ChemSage user. Can I use my ChemSage files in FactSage?

We welcome all those users who have been accessing the ChemSage module through the DOS package. In such a case you have been using specialized databases stored in ChemSage files. In most cases you can import these databases into FactSage. However there are some restrictions and these include:

• the total number of components must not exceed 48
• the total number of solution phases must not exceed 40
• the total number of species must not exceed 1500
• the ChemSage file must be in text (ascii) format

To import a ChemSage file into FactSage go to the Reactants Window of Equilib. Click on 'File > ChemSage files > Information ...' and follow the instructions.

A ChemSage file may contain both pure substance and solution data. On import into FactSage these data are automatically stored in a compound and a solution database. These databases can then be edited and manipulated by the Compound and Solution programs. The data from these databases can be employed in FactSage calculations combined with data from other sources (for example from the FACT and SGTE databases)

You can use the Equilib program to create a ChemSage file. The resulting file could be used as a source of data for ChemSheet and ChemApp applications.

Note: for security reasons the resulting ChemSage file is in binary code (*.cst file) and can only be accessed by users who have a valid security key (dongle) for their ChemSheet and ChemApp applications. It can not then be imported into FactSage (via Equilib for example).

The standard SGTE databases available for ChemSage have names beginning with SSL, SDM, SPS, SOR, SUV and SUN. These abbreviations relate to solutions (SL), dummies (DM), pure substances (PS), organic species (OR), the university database (UV) and the unary database (UN). All of these except the university database (SUV) have found equivalences in the new FactSage environment. SUV however has been dropped for good.

Equivalences:

SSL and SDM
These two databases are now incorporated in the SGTEsoln and SGTEbase database files. SDM contained the so-called dummy phase constituents that need to be used in the SGTE database in order to have FORMAL consistency among the constituents of a phase but that have not yet been thermodynamically assessed. Such constituents are given the Gibbs free energy value ZERO for all temperatures.

Example: BCC_A2 in the Fe-Al-C system. From the Fe-Al system we know the data for the substitutional mixing of Fe and Al on the metallic sites of the body centered cubic phase (all interstitial sites are empty). From the Fe-C system we know the data for the interstitial mixing of C in Fe. There are no data for C on the interstitial sites of a hypothetical BCC_A2 aluminium. Nevertheless, these are required in order to describe the BCC_B2 phase in Fe-Al-C according to the formula (Fe,Al)1(Va,C)3. In such cases it is often a reasonable assumption to give the Gibbs energy of the hypothetical phase constituent Al1C3 the value ZERO for all temperatures. The major interaction of C in the BCC-phase will be that between Fe and C which is known.

In the ChemSage version of the SGTE database it was possible to distinguish such cases explicitly by entering the set of properly assessed data into the SSL part of the database and the unassessed sets into the dummy part (SDM) of the database.

For formal reasons the two parts have been amalgamated. Users who still wish to keep track of the unassessed phase constituents need to make use of the SDM file in ChemSage or let us know.

SPS and SOR
These two database are now combined into the SGPSBase database file. The organic species can now be stepwise included in or excluded from calculations using the 'Data Search' option "Limit organic species CxHy ..." with a specific value for x.

SUN
This database contained all Unary data compiled by SGTE (see CALPHAD 15(4), 1991). These data are the so-called lattice stabilities of the elements in the most commonly used structures. Most of them are contained in phase datasets for metallic substitutional solutions in the SGTEsoln database file.

Users who still wish to make separate use of the SUN database (for new assessments or for testing ideal solutions between so far unmixed elements) should contact us.

For security reasons ChemSage *.cst files are in binary code and can be edited. However you can display a list of all your ChemSage files including a summary of their contents - in the Equilib Reactants Window click on 'File > ChemSage ... > Summary ...'.

10. Other Error Messages and Bugs

10.1 FactSage crashes or refuses to run.

If you are unable to run one of the FactSage modules (Equilib, Phase Diagram, ..) or it keeps crashing then should reset it with the default values. In the FactSage Main Menu click on 'Tools > Reset programs ... ' and follow the instructions.

Please notify us if you experience "fatal crashes" that you can not resolve.

For purposes of clarity we will define a bug as when the program works OK but it appears that the answer is illogical or not correct; and a crash as when the program freezes and gets hung up, or quits without warning.

First check that the problem does not appear here - most problems are documented on this page.

Then please e-mail us and explain the nature of the problem. FactSage has several programs and many windows and many many options, check boxes, command buttons, drop-down menus, status bars, etc. When sending us details about actions you took please try to specify the program name (Equilib, Compound ...), its window name (Reactants Window, Main Window ...) and precisely what you did (I clicked with the mouse right button on ...., or I clicked on the "X" on the top right-hand-side and then got the message...), etc. This will help us to duplicate your actions and remedy the problem. In the case of Equilib (Reaction, Predom, Eph, Results) if necessary please send us a copy of the file "Equi0.dat" (Reac0.dat, Pred0.dat, Eph0.dat, Equi*.dat) that you will find in your FactSage directory - these files define the details and settings of your last calculation.

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