The formatting of PCFF forcefield files

EMC
1

Hi everyone,

I am trying to use the PCFF+ forcefield developed by Materials Design with EMC. They have developed their own proprietary forcefields that I can not share unfortunately. I am trying have EMC read these files, which are very similar to the legacy pcff files given in EMC distribution, but the error output is not very debugging friendly (see attached picture). I was wondering if I could have access to the backend code of EMC (core/script/field/entry.c) so I can see how I can edit the PCFF+ file format. Please let me know if this possible.

Sincerely,
Max

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image720×437 107 KB

2

Hi Max,

EMC interprets cff force field files with formats as they appear with e.g. Materials Studio. I assume that Materials Design follows the same syntax. It looks like you are missing the first line of the .frc force field file, which identifies what force field we are dealing with,

!BIOSYM forcefield 1

EMC checks the first 18 characters of this line, which have to be exactly as stated above. The .dat file is not checked for any characteristics.