wrong simulation times or misleading time counting?

From: Carlos Simoes (caze.mailings_at_gmail.com)
Date: Wed Jan 18 2006 - 17:48:59 CST

Dear all,

    I started using NAMD a couple of months ago and I've been running
some simulations with a 2 fs iteration timestep. More recently, I
noticed that both namdplot and mdenergy analysis over the entire
simulations show them to have only 5 ns instead of 10 ns (as I would
expect), and I'm trying to figure out why. NAMD User's Guide states
that the total amount of simulation time is given by "numsteps x
timestep". Hence, if I'm carrying out one run for 5 000 000 steps,
with a timestep of 2 fs, I shall expect to get a 10 000 000 fs (10 ns)
simulation. Am I right? Moreover, I suppose it won't make any
difference whether I use the "numsteps" flag or the "run" command
(I've been employing the latter). Obviously, I might have missed a
flag, while using the mdenergy script, but, strangely, it correctly
recognizes the 2 fs timestep (when it starts reading the dcd file).

    Thanks for any tip you can come up with, in advance.

Carlos Simoes

This archive was generated by hypermail 2.1.6 : Wed Feb 29 2012 - 15:41:32 CST