Dear Lammps users,
I am trying to simulate the IR spectrum of cristobalite based on NVE molecular dynamics trajectory using lammps, but i got a problem with the number of cores to use. I run the same input script and data file with the same timestep, same dump frequency, but with one process, two processors and three processors respectively. And use the same post-processing package for the two cases, the resulting IR spectrum have the same wavenumber, however differs in the IR intensity. I have tried to create the initial velocity for the atoms the same after reading the lammps documentation, but still can’t fix the problem. I really have no idea how that intensity difference comes from, is that because the 150 ps NVE simulation is not long enough? or someting else wrong with my input scritp. I have post my input script as well as the resulting IR spectum. Any piece of help will be greatly appreciated!!!
Best regards
Jiasen Guo
lammps input script for Sodalite with MZHB
units metal
dimension 3
atom_style full
read_data MZHB_CRI_original.lmp
#velocity all create 0 87287 loop geom
potential
bond_style harmonic
bond_coeff 1 11.650000 1.6200000
angle_style harmonic
angle_coeff 1 3.4000000 109.47000
angle_coeff 2 1.1100000 149.80000
pair_style lj/cut/coul/long 12.000
pair_coeff 1 1 0.0085997000 1.959982864 12.0000
pair_coeff 1 2 0.0052661900 1.758034219 12.0000
pair_coeff 2 2 0.0032249000 1.576892023 12.0000
special_bonds lj 1.0 1.0 1.0 coul 1.0 1.0 1.0
kspace_style ewald 1.0e-4
