Greetings,

I am trying to do a QM/MM calculation using CHARMM and Q-Chem following the steps in the tutorial by Prof. Kaila https://villekaila.com/news/

Using "envi qchemcnt" in the CHARMM input generates the Q-Chem input where “IGDESP” (with the number of atoms in MM) is added in the $rem section. In the new version of QChem, “ESP_Grid” is used instead of “IGDESP”. How can I have control over the code that generates the Q-Chem input so that I modify the keyword IGDESOP into ESP_Grid?

Thank you in advance,
Regards,
Alpha

cd charmm/source
grep -i igdesp */* indicates that igdesp is written to a file in source/gukint/gukini.F90
You can try changing that write statement and recompile.

Thank you Lennart!