Here is a simple system that reproduces the problem (attached). I am using the “30 Nov 2016” version of LAMMPS.
For orthogonal, I get:
Step Temp E_pair E_mol TotEng Press
0 0 868.186 0 868.186 77966.942
Loop time of 9.53674e-07 on 1 procs for 0 steps with 24 atoms
If I uncomment the change box command, I get:
Memory usage per processor = 6.24292 Mbytes
Step Temp E_pair E_mol TotEng Press
0 0 1192.4847 0 1192.4847 120841.36
Loop time of 9.53674e-07 on 1 procs for 0 steps with 24 atoms
Stan
data.singleTIP4P-Ew (497 Bytes)
in.tip4p (470 Bytes)