Rem variable generated by Q-Chem/CHARMM interface unrecognized by Q-Chem

I was trying to use Q-Chem/CHARMM interface to do some QM/MM calculations. I acquired a copy of the academic-free version of CHARMM (“charmm”) and compiled the code. To see if the interface with Q-Chem is functioning well, I went to try some examples under test/cquantumtest (e.g. alanine_qchem.inp) in charmm. I noticed that while it was able to call Q-Chem, all the Q-Chem jobs failed. Looking at the crashed Q-Chem outputs, it turned out that the Q-Chem input automatically generated by charmm contains a rem variable “igdesp 10”, which was not recognized by Q-Chem. Trying out some other examples for the Q-Chem/CHARMM interface gives the same crash so I was wondering if there is any compatibility issue between the two packages.

This is not really a Q-Chem question, but I wish someone who is familiar with this feature could help. Thanks in advance!

The relevant commit that nuked this variable is 29853, and it looks like esp_grid is a drop-in replacement.

Sorry, that’s my fault - some anlman cleanup related to another QM/MM bug and I was working with Lee Woodcock so I’m not sure how it slipped through. But Eric is correct that REM_IGDESP was renamed as REM_ESP_GRID. Someone should submit a ticket and copy Lee on it.

Thanks. I will submit a ticket.

This will be fixed with the Q-Chem 6.0.1 release.