"light" history file
of changes to ChemApp light since its initial release as V2.0.2
- Improved calculational speed for quasichemical model with respect
to version 5.0.0 and 5.0.1.
- Compaq Visual Fortran: boolean shortcut evaluation
- New subroutines
have been incorporated. With these, a chemical equilibrium composition
can be calculated using the last calculated results as estimate.
- The output of streams in
TQSHOW has been modified.
- All constituents of a system may have P-T-dependent molar volumes.
- 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.
- The calculation of integral extensive properties for phases
described by the Quadruplet Quasichemical formalism (SUBG) has
- The treatment of miscibility gaps has been improved.
- The estimation and mimimization routines have been improved.
- The numerical procedure for calculating the volume of gases
has been made more precise.
- 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
d-notes.txt included with each Delphi distribution,
or the corresponding section in the Programmer's Manual for details.
- 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.
- 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.
- Retrieving extended properties for eliminated phases now properly
results in zero values.
- 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.
- 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.
- 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
- A quadruplet quasichemical formalism for condensed nonaqueous
solutions has been implemented. The model name is SUBG.
- 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.
- 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.
- 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
- 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.
- 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.
- For each constituent, 12 instead of 9 Cp- or Gibbs-energy ranges
- 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.
- The routine for calculating starting estimates is improved
with respect to aqueous and dormant phases.
- The calculation of stoichiometric reactions, of miscibility
gaps, and of one-dimensional phase maps have been improved.
- 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.
- Help texts in French are incorporated.
- Five new subroutines for information on sublattices have been
TQGTLC. All mixture phases
are in this respect considered to contain at least one sublattice.
- A subroutine
TQUSED which provides the actual
system size is added.
- The subroutines
have been added. Their use in opening thermochemical data-files
is strongly recommended over
TQOPEN and FORTRAN's
- Transparent files produced by FactSage can be used with ChemApp.
For this purpose, the subroutines
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 (
and ChemApp now identifies itself with a short signature (
- All distributions: The data-file
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.
- All distributions: All example programs (those
included in the distributions as well as those included with the
manual) have been updated.
- Macintosh: All Macintosh distributions have
- Non-FORTRAN language interfaces:
- All interfaces: The subroutines to open and
close files (e.g.
well as the new subroutines
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
- All interfaces: All interfaces have been updated
with respect to the new ChemApp subroutines.
- Visual Basic interface: Fixed bug in interface
code to tqgspc/tqcspc.
V 3.2.2 (release date: 12
- TQSTXP is changed such that extensive properties of streams
can be requested once defined.
- Metallic constituents of phases described by the two-sublattice
ionic formalism (SUBI) can be used as input when setting conditions.
- 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).
- Error in the calculation of extensive properties of SUBI-
and non-magnetic compound energy-phases with sum of stoichiometries
greater than one is corrected.
- Error message included when stream pressures or temperatures
- Fugacities for gas phase constituents are correctly calculated
for pressure units different from bar.
- The convergence parameters of the Gibbs energy minimization
have been improved.
- 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.
- The convergence of the new SUBO model has been improved.
- 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.
- 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.
- Changes to empirical variables have been made in order
to optimize for solution stability and speed.
- Error messages 506 and 507 modified with corresponding
changes in the code.
- In the ChemSage output, mole fraction of system components
are being printed with more digits for phases described by
- 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
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.
- 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 (
- Added error numbers 901 and 902, plus matching descriptions.
These errors occur if the routine
open the specified file (901), or
close it (902). Since
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
Digital® Visual FORTRAN (Intel®) added.
Lahey® FORTRAN F95 added.
Sun Sparc Solaris® added.
V 2.0.4 (release date: 16
Improved solution stability for the GAYE model.
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.htm (one of which you are currently reading),
README.htm (HTML version of
as well as
a list of known bugs of the current version of ChemApp).
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
Changed description for
to reflect the fact that they are not only used to open thermochemical
data-files, but also to open files that
TQSHOW should write to.
V 2.0.2 (release date: 13
- Initial release of ChemApp light.
Digital is a registered trademark of Digital Equipment Corporation.
Intel and Pentium are registered trademarks of Intel Corporation.
Sun and Solaris are registered trademarks of Sun Microsystems, Inc.
Sparc is a registered trademark of Sparc International, Inc.
Delphi is a registered trademark of Borland.
Lahey is a registered trademark of Lahey Computer Systems, Inc.
Watcom is a registered trademark of Watcom International Corp.
GTT-Technologies, 5 June 2003