I am very new to doing QM/MM calculations in qchem.
I want to do a QM/MM calculation of a crystal structure (42 molecules). I downloaded .cif file. I have XYZ coordinated of that file.
Can anyone suggest to me which interface will be useful for crystal structure to make the .inp file?
So that I can run file in qchem software.
I have used Avogadro to read .cif files and create supercells, and to convert those to xyz coordinates, although it sometimes takes some editing to delete unwanted molecules.
yes that i did but only with xyz coordinates, job is not running in qchem software.
I checked the qchem manual also for QMMM method, there are some codes mentioned like tinker, charmm. if i am not wrong.
I want to know which software is better to make input to run job in qchem software.
I think (?) what you are asking is how to setup force field parameters for the MM part of a QM/MM job. Q-Chem does not do this for you, you need to find a 3rd-party program or else do it manually. There are interfaces to several popular MM packages (e.g., GROMACS) and those programs may have tools to do this.
@jherbert, can you explain to me how I can set the force field parameters manually?
though I really suggest using an interface to a proper MM program like CHARMM or GROMACS.