I parameterized my own SNAP + ZBL potential for silicon, see the attached files and following pairstyle commands:
pair_style hybrid/overlay zbl 3.8 5.03 snap
pair_coeff 1 1 zbl 14 14
pair_coeff * * snap Si.snapcoeffs Si Si.snapparams Si
This potential works for my purposes, except I’d like to extend SNAP to a longer cutoff.
During parameterization, I let the cutoff vary from 1st nearest neighbors to 4th nearest neighbors. Every optimized solution preferred a cutoff of 1st nearest neighbors. When I try to fix the cutoff at a longer distance, the optimization isn’t successful and a good solution cannot be found.
Possible issues are that I’m fixing the number of SNAP coefficients…
Do I need more SNAP coefficients when using a longer cutoff? Does anyone know how can I successfully use the SNAP potential for longer cutoff distances?
Thanks for your time.
Si.snapcoeffs (405 Bytes)
Si.snapparams (97 Bytes)