Dear users,<br><br>Upon was trying to simulate an npt ensemble (protein in water),<br>pressure was coupled using parinello rahman system with tau_p = 2,<br>tau_t = 1; compressibility 4.5e-5, type = isotropic.<br><br>(cut off scheme (vdw_type = switch; rvdw = 1.0; rvdw_switch = 0.9;<br>
rcoulomb = 1.2; rlist = 1.2).<br><br>No matter what value of tau_p is used (0.5, 1, 2, 2.5, 3, 3.5), the pressure<br>fluctuations are very drastic. I have gone through the mailing list regarding <br>this issue but could not come to any conclusion.<br>
<br>Any suggestions are helpfull.<br><br>This is one of the statistics for pressure fluctuations.<br><br>Statistics over 500001 steps [ 0.0000 through 1000.0000 ps ], 1 data sets<br>All statistics are over 100001 points<br>
<br>Energy Average Err.Est. RMSD Tot-Drift<br>-------------------------------------------------------------------------------<br>Pressure 5.77629 0.99 398.013 -5.34218 (bar)<br>
<br><br>Thanking you<br>With Regards<br>M. Kavyashree<br>