Dear lammps users,
I had some questions on neighbor list and periodic boundary condition when I tried to understand the source code of pair_lj_cut.cpp. I really appreciate your help.
(1) With 3D periodic boundary condition and a simple cubic lattice system, I checked jnum for each particle i and found that every particle had different number of neighbors. I guess if particle j is in particle i's neighbor list, then i will not be in j's list. Is it right? Can someone explain a bit that ideally how the neighbor list is constructed?
(2) In pair_lj_cut.cpp, the relative distance between i and j (if they are neighbors) is calculated as
xtmp = x[i];
ytmp = x[i];
ztmp = x[i];
delx = xtmp-x[j];
dely = ytmp-x[j];
delz = ztmp-x[j];
rsq = delx*delx + dely*dely + delz*delz;
and there is no nearest periodic boundary image correction, why?
I was using lammps 22Jan08 release and the input and data files are attached. Thanks,
data.lj (17.8 KB)
in.lj (542 Bytes)