[gmx-users] add external force

[Ting Zhou]

On 06/08/2010 11:18 AM, Mark Abraham wrote:
>
>
> ----- Original Message -----
> From: Ting Zhou <coomteng at gmail.com>
> Date: Tuesday, June 8, 2010 19:13
> Subject: [gmx-users] add external force
> To: gmx-users at gromacs.org
>
>  > Hi,
>  >
>  > I would like to add an external force f(x) on some atoms during
>  > the simulation, where x is the Cartesian coordinates of these atoms.
>  >
>  > Each component of the force can only be calculated with the
>  > whole set of coordinates, i.e., (f1, f2, ..., fn) = f(x1, x2,
>  > ..., xn)
>
> If you potentially need to know every coordinate to calculate each
> force, then you will have to either run in serial, or emulate the
> behaviour in write_trxframe to gather the coordinates and scatter the
> forces at useful time.
>
> Mark
>
Are you talking about modifying the source? Is there a lagged script 
interface to calculate forces?
Best,
Ting