Hello,<div><br></div><div>I am running MDs on a linux PC with OpenSuse, using:</div><div><br></div><div>mpirun -np 4 mdrun -v -dlb auto -reprod ....</div><div><br></div><div>If I repeat the calculation on the same PC, I get the same result. If I change to another PC with RedHat I get a different result. More specifically, I am calculating a deviation from experiment, which varies by ~20 % on changing operating systems (pretty much the same hardware on both PCs). Is there any way to avoid such variations? I guess I am missing something in the mdp file, which is: </div>
<div><br></div><div><div>cpp = /usr/bin/cpp -traditional</div><div>integrator = sd</div><div>tinit = 0</div><div>dt = 0.002</div><div>nsteps = 1000000</div>
<div><br></div><div>nstcomm = 1</div><div>nstcalcenergy = 1</div><div>nstxout = 5</div><div>nstvout = 100</div><div>nstlog = 100</div><div>nstenergy = 100</div>
<div><br></div><div>nstlist = 5</div><div>ns_type = grid</div><div><br></div><div>pbc = xyz</div><div>rlist = 0.9</div><div><br></div><div>optimize_fft = yes</div>
<div>coulombtype = pme</div><div>rcoulomb = 0.9</div><div>epsilon-r = 1</div><div>rvdw = 0.9</div></div><div><br></div><div><div>constraints = all-bonds</div>
<div>constraint-algorithm = Lincs</div><div><br></div><div>unconstrained-start = yes</div><div>lincs-warnangle = 30</div></div><div><div><br></div><div>tc_grps = System</div><div>tau_t = 0.1</div>
<div>ref_t = 300.0</div><div><br></div><div>Pcoupl = parrinello-rahman</div><div>tau_p = 2</div><div>compressibility = 4.5e-05</div><div>ref_p = 1.0</div>
<div><br></div><div>gen_vel = yes</div><div>gen_temp = 300.0</div><div>gen_seed = 173529</div><div><br></div><div><br></div></div><div>Many thanks for your help,</div><div>
Igor</div>