ChemApp "light" history file
List of changes to ChemApp light since its initial release as V2.0.2

V 5.0.2

  • ChemApp:

    1. Improved calculational speed for quasichemical model with respect to version 5.0.0 and 5.0.1.

    V 5.0.1

  • Distributions:

    1. Compaq Visual Fortran: boolean shortcut evaluation issue resolved.

    V 5.0.0

  • ChemApp:

    1. New subroutines TQCEN and TQCENL have been incorporated. With these, a chemical equilibrium composition can be calculated using the last calculated results as estimate.

    2. The output of streams in TQSHOW has been modified.

    3. All constituents of a system may have P-T-dependent molar volumes.

    4. In addition to three different Helgeson models (HTSZ with ideal mixing, HTWZ with Debye-Hueckel, HTDZ with Davies) one which combines Helgeson, Debye-Hueckel and Pitzer has been incorported. The model name is PIHZ.

    5. The calculation of integral extensive properties for phases described by the Quadruplet Quasichemical formalism (SUBG) has been corrected.

    6. The treatment of miscibility gaps has been improved.

    7. The estimation and mimimization routines have been improved.

    8. The numerical procedure for calculating the volume of gases has been made more precise.

  • Distributions:

    1. Borland Delphi: the Delphi version of ChemApp now uses conditional defines set by the user to determine which ChemApp DLL (standard, extended, or light) should be use for a particular application program. See the Delphi notes in d-notes.txt included with each Delphi distribution, or the corresponding section in the Programmer's Manual for details.

    V 4.1.3

  • ChemApp:

    1. The maximum number of Gibbs energy/heat capacity equations for a constituent (see parameter NI in subroutine TQSIZE) has been increased from 12 to 20.

    V 4.1.2

  • ChemApp:

    1. The maximum number of excess Gibbs energy coefficients for a mixture phase has been increased from 300 to 2000 for the extended version of ChemApp.

    2. Retrieving extended properties for eliminated phases now properly results in zero values.

  • Distributions:

    1. Selected distributions: Starting with selected distributions, special versions of the ChemApp libraries and DLLs are now included, which are compiled with the maximum possible optimization level for the compiler used. Plese read the important notes in the README.txt file of your distribution if you are interested in using these optimized versions.

    V 4.0.1

  • ChemApp:

    1. The calculation of osmotic coefficients for the Davies formalism (IDDZ) has been corrected. A new aqueous model, the specific ion-interaction formalism (SITZ), has been implemented. A system may simultaneously contain several aqueous phases.

    2. An extended compound energy formalism (SUBE), which combines standard Gibbs energies input according to the compound energy formalism (SUBL) with excess Gibbs energies input according to the species chemical potential/bond energy formalism (SUBS), has been implemented.

    3. A quadruplet quasichemical formalism for condensed nonaqueous solutions has been implemented. The model name is SUBG.

    4. The models RKXP, KKOP, KKXP and MARP have been deleted. Please contact GTT-Technologies for replacement of old files, should they make use of these models.

    5. Kohler/Toop extrapolation has been generalized. If for a given ternary system the group numbers of the components are all equal or all unequal, Kohler will be made, else Toop.

    6. ChemApp now supports user-defined solution models. Users of ChemApp who need to work with their own Gibbs energy models in the complex equilibrium calculations they perform should contact GTT-Technologies for a special version of ChemApp which supports this feature.

    7. Stoichimetries for stoichiometric condensed phases entered in the system data-file are no longer altered internally to correspond exactly to a fraction, e.g., A(1/3)B(2/3). The stoichiometry matrix in the system data-file now contains more digits. These modifications might lead to small changes in the output.

    8. The total number of phases which are considered during the course of a minimization has been increased from 30 to 60. System data-files could thus in principle be made bigger.

    9. For each constituent, 12 instead of 9 Cp- or Gibbs-energy ranges are permitted.

    10. The extensive properties are still calculated from Gibbs energies through a numerical procedure, but within this, phase compositions might now change. This would normally only lead to a change in the calculated heat capacity values.

    11. The routine for calculating starting estimates is improved with respect to aqueous and dormant phases.

    12. The calculation of stoichiometric reactions, of miscibility gaps, and of one-dimensional phase maps have been improved.

    13. Convergence for the modified quasichemical formalism, with or without solutes (QSOL/QUAS), has been improved. Very small concentrations of solutes are now permitted. Equations for estimating activities of QSOL constituents have been improved. This might lead to small changes in the output. Extensive property calculations for QSOL/QUAS have been corrected for cases when subsystems of a system data-file are used as input.

    14. Help texts in French are incorporated.

    15. Five new subroutines for information on sublattices have been incorporated: TQINLC, TQGNLC, TQNOSL, TQNOLC, and TQGTLC. All mixture phases are in this respect considered to contain at least one sublattice.

    16. A subroutine TQUSED which provides the actual system size is added.

    17. The subroutines TQOPNA and TQOPNB have been added. Their use in opening thermochemical data-files is strongly recommended over TQOPEN and FORTRAN's OPEN.

    18. Transparent files produced by FactSage can be used with ChemApp. For this purpose, the subroutines TQOPNT, TQRCST, and TQGTRH have been added. Also to allow for transparent file support, all regular ChemApp versions are now personalized with the licensee's ID and name (TQGTID and TQGTNM), and ChemApp now identifies itself with a short signature (TQGTPI).

  • Distributions:

    1. All distributions: The data-file SUBL-EX.DAT is now part of the ChemApp distribution. Its main purpose is to serve as an example data-file for the demonstration of the various sublattice model subroutines.

    2. All distributions: All example programs (those included in the distributions as well as those included with the manual) have been updated.

    3. Macintosh: All Macintosh distributions have been discontinued.

  • Non-FORTRAN language interfaces:

    1. All interfaces: The subroutines to open and close files (e.g. TQOPEN, TQCLOS, as well as the new subroutines TQOPNA, TQOPNB, and TQOPNT) are now part of the FORTRAN core code. This is mainly due to the fact that even when programming with ChemApp FORTRAN, the use of these subroutines is recommended over FORTRAN's OPEN and CLOSE.

    2. All interfaces: All interfaces have been updated with respect to the new ChemApp subroutines.

    3. Visual Basic interface: Fixed bug in interface code to tqgspc/tqcspc.

    V 3.2.2 (release date: 12 April 1999)

    • ChemApp:

      1. TQSTXP is changed such that extensive properties of streams can be requested once defined.

      2. Metallic constituents of phases described by the two-sublattice ionic formalism (SUBI) can be used as input when setting conditions.

      3. Dormant and eliminated phases and constituents are given in TQSHOW as well as the selected system units and the target limits (when a target is defined).

      4. Error in the calculation of extensive properties of SUBI- and non-magnetic compound energy-phases with sum of stoichiometries greater than one is corrected.

      5. Error message included when stream pressures or temperatures are negative.

      6. Fugacities for gas phase constituents are correctly calculated for pressure units different from bar.

      7. The convergence parameters of the Gibbs energy minimization have been improved.

      8. A new subroutine TQPCIS for checking if a constituent is permitted as incoming is introduced. In the new version, this only applies to constituents of phases described by the rarely used model SUBS.

      9. The convergence of the new SUBO model has been improved.

      10. If the sublattice arrangement of a phase is defined such that all sublattices contain vacancies as one constituent, the phase might form empty, i.e., it might contain nothing but vacancies. In the new version this cannot happen if the phase in entered in two copies.

      11. When possible, the chemical potentials of all system components are calculated also for stoichiometric reactions, for instance in the case when the system contains two system components but only one stoichiometric phase is formed at equilibrium. This is done by setting the activities of a number of proper stoichiometric phases equal to unity, this number being equal to the number of non-defined chemical potentials.

      12. Changes to empirical variables have been made in order to optimize for solution stability and speed.

      13. Error messages 506 and 507 modified with corresponding changes in the code.

      14. In the ChemSage output, mole fraction of system components are being printed with more digits for phases described by SUBS.

      15. Up until the version 2.1.0, ChemApp did not give a proper error message if one tried to define more streams, or more stream constituents, than possible.

        The maximum for both is the maximum number of constituents of the version of ChemApp used (see parameter NA in TQSIZE). This value is 30 for the light version of ChemApp. This release of ChemApp now contains a proper error number and error message for this case.

      16. Safe extrapolation added. This concept, which can be applied to any mixture phase model, allows for a per-constituent penalty to the Gibbs energy beyond a specified concentration. Using this new feature, a phase can be made metastable at compositions where the mixture phase model alone would predict it to be stable. This new feature is used with models which only give, because of their very nature, correct results at low concentrations of some or all its phase constituents, for instance the dilute solution model based on the Wagner approach (WAGN).

      17. Added error numbers 901 and 902, plus matching descriptions. These errors occur if the routine TQOPEN cannot open the specified file (901), or TQCLOS cannot close it (902). Since TQOPEN and TQCLOS are not part of ChemApp themselves, but of the interface between ChemApp and other languages than FORTRAN (e.g. C/C++, Borland Delphi), this change does not affect FORTRAN application programs of ChemApp.

    • Distributions:
      Digital Visual FORTRAN (Intel) added.
      Lahey FORTRAN F95 added.
      Sun Sparc Solaris added.

    V 2.0.4 (release date: 16 March 1998)

    • ChemApp:
      Improved solution stability for the GAYE model.

    • Distributions:
      Borland Delphi version added.
      Lahey FORTRAN LF90 (DOS) added.
      Watcom FORTRAN F77 (DOS) added.

      Language Systems FORTRAN (Macintosh): ChemFile is now included.

      Every distribution now also contains the files history.txt, history.htm (one of which you are currently reading), README.htm (HTML version of README.TXT), as well as BUGS.TXT and BUGS.htm (containing a list of known bugs of the current version of ChemApp).

    • Documentation:
      Changed layout of table of contents (HTML version), it is now written in a smaller fontsize and includes links to the individual ChemApp subroutines too.

      The files containing the notes for various programming languages are now called f-notes.txt / f-notes.htm (FORTRAN), c-notes.txt / c-notes.htm (C/C++), and d-notes.txt / d-notes.htm (Borland Delphi).

      Changed description for TQOPEN/TQCLOS to reflect the fact that they are not only used to open thermochemical data-files, but also to open files that TQCEL and TQSHOW should write to.

    V 2.0.2 (release date: 13 January 1998)

    • Initial release of ChemApp light.

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    Sparc is a registered trademark of Sparc International, Inc.
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    Lahey is a registered trademark of Lahey Computer Systems, Inc.
    Watcom is a registered trademark of Watcom International Corp.

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