[gmx-users] Timestep

van Bemmelen J.J.M.vanBemmelen at student.TUDelft.NL
Tue Aug 7 21:23:55 CEST 2007


Ramya,

A timestep of dt=0.002 already means a timestep of 2fs, since the unit
of dt is ps. So a timestep of dt=0.002=2 fs works fine for you, which is
perfectly normal. If you want to go higher you need to use certain
tricks, as suggested by Xavier.

I suggest you read the manual (e.g.
http://www.gromacs.org/documentation/reference/online/mdp_opt.html )
first before asking this kind of confusing questions.

mzzls,
Jeroen


>Date: Tue, 7 Aug 2007 22:52:01 +0530 (IST)
>From: "Ramya Cherukupalli" <ramya at research.iiit.ac.in>
>Subject: [gmx-users] Timestep
>To: "Discussion list for GROMACS users" <gmx-users at gromacs.org>
>Message-ID: <54862.192.168.36.204.1186507321.squirrel at 192.168.36.250>
>Content-Type: text/plain;charset=iso-8859-1
>
>
>Hello..
>
>  Thanks to Xavier for his prompt reply..
>
>  Actually my objective is a bit longer[50-60ns] but the 
>problem is that
>even if i cant change the time-step to 0.003 it is exiting saying
>segmentation fault then how is it possible with 1fs [or 4 fs as
>suggested] which i want to do to reduce time.
>  I wanted to know where the problem is... why cant i increase the time
>step and the only error shown is 'segmentation fault'..so is the reason
>in compilation or coding or machine precision or is it with molecular
>system wise thats what i was trying to understand..
>
>Thanks again..
>Ramya.



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