Re: [lammps-users] Aluminum/Nickel/Oxygen force field

Dear LAMMPS list,

We want to use the Zhou CTIP potential. As already mentioned in the list, the addition of Zhou to the original Streitz-Mintmire potential is the two terms to bound the charges. If we consider a metallic alloy with an oxide, the bounding of the charges allows to have zero charges in the pure metallic alloys and to prevent charge unphysical oscillations when considering a compressed oxide.

These two terms seems not to be implement in the "fix qeq/slater ».

According to the below message on the topic, Ray Shan suggested to « create multiple dummy atom types to surrogate other types of metal and oxygen » and « to exclude certain metal atoms at the interface from charge equilibration » .

I don't understand how this is can be equivalent to Zhou terms to bound the charges and how it will prevent the appearance of charges in the pure metallic parts of alloys.

Shall we create a dynamic group to exclude metallic atoms that have no oxygen neighbors in the cutoff radius for charge-charge interactions to exclude them from the charge equilibration (qeq/slater) fix ? Is there any simple LAMMPS command to do this efficiently ?

Many thanks for your help. Best regards,