[lammps-users] Kspace style with TIP4P potential

Dear LAMMPS users,

I have a quick question. I saw there is a restriction that “When using a long-range pairwise TIP4P potential, you must use kspace style pppm/tip4p and vice versa”. I am wondering why it is must. Why not Ewald does work?

Most appreciated.

Best
Yajie

2009/6/30 Yajie Lei <[email protected]…1044…>

Dear LAMMPS users,

I have a quick question. I saw there is a restriction that “When using a long-range pairwise TIP4P potential, you must use kspace style pppm/tip4p and vice versa”. I am wondering why it is must. Why not Ewald does work?

Most appreciated.

The pppm/tip4p shifts the position of the negative charge associated with the oxygen atom to the proper location before computing the electric field and long-range forces. The regular Ewald style does not do this, and therefore does not correctly calculate these quantities.

–AEI