Hi All,
I’m able to run LAMMPS without error. Here is my in file:
units metal
boundary p p p
atom_style atomic
read_data data.Cu_8x8x8
pair_style eam/fs
pair_coeff * * Cu.eam.fs Cu
neighbor 0.3 bin
neigh_modify delay 10
fix 1 all nve
thermo 10
timestep 0.001
dump 1 all atom 10 dump.meam
run 100
I’ve taken the potential file from http://www.ctcms.nist.gov/potentials/Cu.html. I exported my data file from Materials Studio where I created an 8x8x8 unit cell of FCC Cu. As I said, the script executes without error but I am dumping some non-physical results for the energy and pressure:
LAMMPS (9 Aug 2010)
Reading data file …
orthogonal box = (0 0 0) to (28.9176 28.9176 28.9176)
1 by 1 by 1 processor grid
2048 atoms
Setting up run …
Memory usage per processor = 1.89731 Mbytes
Step Temp E_pair E_mol TotEng Press
0 0 inf 0 inf nan
10 nan -6375.4825 0 nan nan
20 nan -6375.7383 0 nan nan
30 nan -6375.2207 0 nan nan
40 nan -6374.2325 0 nan nan
50 nan -6373.3726 0 nan nan
60 nan -6373.1891 0 nan nan
70 nan -6373.8155 0 nan nan
80 nan -6374.8678 0 nan nan
90 nan -6375.7074 0 nan nan
100 nan -6375.8718 0 nan nan
Loop time of 1.34835 on 1 procs for 100 steps with 2048 atoms
Pair time () = 1.13639 (84.2797)
Neigh time () = 0.059721 (4.42918)
Comm time () = 0.022197 (1.64623)
Outpt time () = 0.042343 (3.14035)
Other time (%) = 0.087704 (6.50452)
Nlocal: 2048 ave 2048 max 2048 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Nghost: 2120 ave 2120 max 2120 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Neighs: 36378 ave 36378 max 36378 min
Histogram: 1 0 0 0 0 0 0 0 0 0
Total # of neighbors = 36378
Ave neighs/atom = 17.7627
Neighbor list builds = 2
Dangerous builds = 0
My question at this point is mainly regarding the things I can do to change the intital conditions that are being printed out for step 0. Why am I starting with infinite energy and the pressure is not a number? Also, what is the E_Pair a measure of that it can start as infinite and then become finite once the dynamics are involved?
Thanks,
Jonathan Tooker