FAQ Group: ChemApp

10.1 V 5.0, 14 April 2003

Added: section 2.10: Does ChemApp require a hardware key, like FactSage and ChemSheet do? Added: section 6.4: ChemApp is fast, but I need it to be even faster, what can I do? Added section 5.6: I would like to use data from my FactSage databases with ChemApp. Does ChemApp require direct access to the FactSage databases, i.e. does …

10.1 V 5.0, 14 April 2003 Read More »

9.1 I’m trying to set up a MFC application under Microsoft Visual C++, but I get error messages relating to precompiled header files, what to do?

This problem is very likely not related to ChemApp, but to an incorrect setup of support for precompiled header files in your project. One remedy is to open your “Project Settings” dialog, tab “C/C++”, category “Precompiled Headers”, and choose either “Not using precompiled headers” or “Automatic use of precompiled headers”. Both settings should work.

9.2 I’m using ChemApp on a Unix system and I get several “undefined symbol” errors during linking, what to do?

The undefined symbols reported by the linker usually start with one or two underscores, and reported to be first referenced in the ChemApp library. This happens during the linking of any ChemApp application program, even the demo programs (e.g.cademo1) included with the ChemApp distribution. Solution: The cause of this error is typically related to the …

9.2 I’m using ChemApp on a Unix system and I get several “undefined symbol” errors during linking, what to do? Read More »

8.2 ChemApp does not read a data-file properly, how do I find out what is wrong?

If an error occurs (error no. 103 or 102) while reading the thermodynamic data-file using TQRFIL (Read – File), the reason is typically one of the following: The file has not been opened properly.  This can especially happen when the subroutine TQOPEN (Open – File) is used (i.e. when programming in languages other than FORTRAN) …

8.2 ChemApp does not read a data-file properly, how do I find out what is wrong? Read More »

8.3 ChemApp says it cannot calculate an equilibrium, what is wrong?

If ChemApp indicates that it cannot calculate an equilibrium, typically returning error numbers 701 or 702 after a call to TQCE (Calculate – Equilibrium) or TQCEL (Calculate – Equilibrium – List – Results), check the conditions which are active for the equilibrium calculation in question using TQSHOW (Show – Present – Settings). Then check the …

8.3 ChemApp says it cannot calculate an equilibrium, what is wrong? Read More »

8.4 I want to retrieve Cp/H/S/G for a phase constituent, do I use TQGETR or TQGDPC?

Both TQGETR (Get – Results) and TQGDPC (Get – Thermodynamic – Data – Phase – Constituent) allow you to retrieve the values for these thermodynamic functions for phase constituents. The difference is that TQGETR retrieves these values for the previously calculated equilibrium state. The values retrieved with TQGDPC, on the other hand, have nothing to do …

8.4 I want to retrieve Cp/H/S/G for a phase constituent, do I use TQGETR or TQGDPC? Read More »

8.5 I’m performing a calculation at constant volume and it fails, what can I do about it?

The answer in short: Perform a target calculation with volume as target and pressure as target variable instead. When calculations are made under constant product volume by using the option ‘VT’ of the subroutines TQSETC (Set – Equilibrium – Condition) or TQSTEC (Set – Equilibrium – Condition – When – Stream – Input), ChemApp will …

8.5 I’m performing a calculation at constant volume and it fails, what can I do about it? Read More »

8.6 Why do the results I retrieve with TQSTXP look wrong or are all zero?

For users of ChemApp versions prior to 3.2.0: The values returned by TQSTXP (Get – Thermodynamic – Property – Of – A – Stream) always refer to the last calculated equilibrium state. If TQSTXP is called before the first equilibrium calculation has been performed using TQCE (Calculate – Equilibrium) or TQMAP (Calculate – One – …

8.6 Why do the results I retrieve with TQSTXP look wrong or are all zero? Read More »