QUESTION about transfer a force filed from GULP to LAMMPS

Hi lammps users,

thanks for the reply Stan, but how would that gewald parameter (did you mean that gewald = eta?) effect the coulomb interaction energy. in GULP, this parameter is included in a erfc function show as follows:


and i run test single point calculation with only electrostatic potential in lammps with different gewald values, it did’t show any total energy difference when this parameter is larger than the optimal value found by (gewald 0), just change the real part energy and the reciprocal part energy, the 0.0005 ev energy difference between GULP and lammps is still there.

Best Regards

Jiasen Guo

Is your concern that the total energy between LAMMPS and GULP are different by 0.0005 ev? LAMMPS and GULP may not have the same accuracy metric. First I would try increasing the real space cutoff and the kspace accuracy to get a highly converged total energy value. Then see if that matches for LAMMPS and GULP.