[gmx-users] Re: Simulations backward in time

[Vitaly Chaban]

Yes. Namely at the very step the velocities should be inverted to
invert a time flow.

My remark was addressed namely to the word "initial".


2008/8/21 Berk Hess <gmx3 at hotmail.com>:
> Surely inverting the velocities changes the direction of the system
> evolution.
> The state of the system is given by x and v. The evolution is determined
> by the state and the potential. The only time direction information is in
> the sign of v.
> Note that due to numerical issues you will never get back the inverse of
> an original trajectory when inverting the velocities.
>
> Berk
>
>
> ________________________________
>> Date: Thu, 21 Aug 2008 16:53:07 +0300
>> From: chaban at univer.kharkov.ua
>> To: jhub at gwdg.de; gmx-users at gromacs.org
>> Subject: Re: [gmx-users] Re: Simulations backward in time
>> CC:
>>
>> In conf.gro? It will change only the first steps but will not change
>> the direction of the system evolution.
>>
>> As I understand, the topicstarter wanted to perform the simulation
>> "backwards"...
>>
>> Vitaly
>>
>> 2008/8/21 Jochen Hub <jhub at gwdg.de>:
>> > Vitaly Chaban wrote:
>> >>>
>> >>> I wanted to perform some simulations backward and forward in time (for
>> >>> transition path sampling ). If I specify a negative value for 'dt' in
>> >>> the
>> >>> mdp file, would that work for backward integration of the equations of
>> >>> motion ?
>> >>>
>> >
>> > You could also invert the initial velocities. Shouldn't that be the same
>> > as
>> > using a negative dt ?
>> >
>> > jochen
>> >
>> > --
>> > ************************************************
>> > Dr. Jochen Hub
>> > Max Planck Institute for Biophysical Chemistry
>> > Computational biomolecular dynamics group
>> > Am Fassberg 11
>> > D-37077 Goettingen, Germany
>> > Email: jhub[at]gwdg.de
>> > Tel.: +49 (0)551 201-2312
>> > ************************************************
>> >
>>
>>
>>
>> --
>> Vitaly V. Chaban
>> School of Chemistry
>> National University of Kharkiv
>> Svoboda sq., 4, Kharkiv 61077, Ukraine
>> email: chaban at univer.kharkov.ua
>> skype: vvchaban
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-- 
Vitaly V. Chaban
School of Chemistry
National University of Kharkiv
Svoboda sq., 4, Kharkiv 61077, Ukraine
email: chaban at univer.kharkov.ua
skype: vvchaban