IUBio GIL .. BIOSCI/Bionet News .. Biosequences .. Software .. FTP

restart files

abonvin at igc.phys.chem.ethz.ch abonvin at igc.phys.chem.ethz.ch
Wed May 28 02:31:08 EST 1997


>I have a question about restart files in xplor.  
>
>Should a trajectory that is pieced together using restart files be 
>identical to the trajectory obtained from a single continuous calculation?
>I would think the answer is yes, but the following test case suggests
>otherwise.

I have here to contradict somewhat Gerard statement: the energies won't
be similar in most of the cases. The difference however should remain
very small. This is due to the way the non-bonded pair list is updated
in X-Plor, i.e. each time an atom moves by more than typically 0.5 A.
When you restart you simulation, the non-bonded pair list will be
reevaluated, while with a continuous trajectory this might not be the
case at the exact same time point. This will lead to small differences.
Of course the randomness effect pointed out by Gerard will also come on
top of that.

Cheers,
Alexandre

==========================================================================
| Dr. Alexandre Bonvin           | Phone: Int+41-1-632-5504              |
| Physical Chemistry, ETHZ       | Fax:   Int+41-1-632-1039              |
| Universitatstrasse 6           | Email: abonvin at igc.phys.chem.ethz.ch  |
| 8092 Zurich, Switzerland       | http://igc.chem.ethz.ch/abonvin       | 
==========================================================================




More information about the X-plor mailing list

Send comments to us at archive@iubioarchive.bio.net