<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear gmx-developers,<div><br></div><div>After having a look to gromacs source code for quite a long time, I am still wondering in where initial velocities generated using the grompp utility (I assume v(t0)) are shifted to v(t0 - dt/2) in order to start the leap-frog algorithm in "update.c"</div><div><br></div><div>Could anybody shed some light in this issue?</div><div><br></div><div>Thanks in advance for your help,</div><div><br></div><div>Pablo</div><div><br></div><div>_____________________________________________</div><div>Pablo Campomanes</div><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 12px; ">Laboratory of Computational Chemistry and Biochemistry </span></div><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Arial, Helvetica, sans-serif; font-size: 12px; ">BCH 4118 EPF Lausanne</span></div></body></html>