[XtalOpt-devel] shell model in GULP

[Wei Lai]

Dear Users,

I am a new user of XtalOpt and have a couple of questions regarding
the implementation of GULP shell model in XtalOpt. The test structure
is MgO with core/shell for O and core only for Mg.

1) It seems "gulpFracShell" forces both Mg and O to adopt core/shell
models. How can we use core for Mg and core/shell for O?

2) If we already know the positions of Mg and we just want to relax O
positions, how can we apply fixed positions (fixed fractional
coordinate) to Mg only?

Thanks.

Regards, Wei

Wei Lai
Michigan State University