KiSThelP website

KiSThelP - a program to predict thermodynamic properties and rate constants from quantum chemistry results.


Frequently Asked Questions

  1. On double-clicking on the Kisthelp java icon (kisthelpXXXX.jar), it causes the file to be opened in the archive manager instead of being executed: right-click the icon and select to open it with the JRE ("Java Runtime Environment")
  2. The program always freezes when I do TST calculations when reading frequencies values : The imaginary frequency must be entered as "3000i" and not "-3000" in the .kinp input file. Whenever possible, the best is to let KiSThelP read the quantum chemistry outputfile (Gaussian, NWCHEM, Gamess, ORCA, MOLPRO).
  3. I want to know if kisthelp do some rate calculation using gaussian outfile by CBS-QB3 method ? because cbs-qb3 method does not output frequency files separately. This kind of method (CBS) performs multi-job calculations. Such composite approach will combine the results of several calculations so that the KiSThelP parser cannot read the associated output file. However, in that case, you can manually build (see KiSThelP documentation) the KiSThelP input file (.kinp) so that to select the appropriate potential energy, the appropriate vibrational frequencies ...
  4. I have a question regarding the RRKM calculations for which I could not find the answer in your paper, https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcc.23470. For RRKM rate constant (Equation 21 in the paper), effective collision frequency (ω) is found through ω=βc ZLJ [M] in the program. Can you please let me know the expressions for the two terms, βc and ZLJ (collisional efficiency and Lennard–Jones collision frequency), as I could not find them in the paper. βc corresponds to a numerical value representing the collisional efficiency. In our paper [E. Henon et al., Phys. Chem. Chem. Phys. 5 (2003) 5431] we decided to choose βc=0.2 for N2 and for the formaldehyde. For more details please refer to the paper by J. Troe J. Chem. Phys. 66, 4745 (1977). Z_LJ is defined in the paper by Troe and it is a function of the Lennard Jones diameters and potential wells, we used equations (3.1) and (3.3) of the Troe reference [J. Chem. Phys. 66, 4758 (1977)]. Some of these parameters can be found in the KiSThelP menu Data/Lennard-Jones parameters for many species or analogues.

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