Re: Pulling only one half of a harmonic restraint

From: Miro Astore (miro.astore_at_gmail.com)
Date: Fri Sep 13 2019 - 04:26:13 CDT

Thank you!

On Fri., 13 Sep. 2019, 19:20 Jérôme Hénin, <jerome.henin_at_ibpc.fr> wrote:

> Hi Miro,
>
> Within the atom group block you can specify: "enableForces off".
> Of course this changes the physics of what the harmonic restraint does:
> the net force is halved (effectively halving the force constant), and its
> net contribution to center-of-mass motion becomes nonzero.
>
> Jerome
>
> On Fri, 13 Sep 2019 at 10:06, Miro Astore <miro.astore_at_gmail.com> wrote:
>
>> Hi all,
>>
>> I would like to pull on the atoms in group1 but not the ones in group 2.
>> Help on how to do this would be appreciated. Example Colvar below
>>
>> colvarsTrajFrequency 500
>> # Pulling
>> colvar {
>> name Pulled
>> outputAppliedForce yes
>> distance {
>> group1 {
>> atomsFile atoms.pdb
>> atomsCol O
>> atomsColValue 1.0
>> }
>> group2 {
>> atomsFile atoms.pdb
>> atomsCol O
>> atomsColValue 2.0
>> }
>> }
>> }
>> harmonic {
>> colvars Pulled
>> centers 34
>> targetCenters 4
>> targetNumSteps 30000
>> forceConstant 4.0
>> }
>>
>> Best, Miro
>>
>

This archive was generated by hypermail 2.1.6 : Sat Dec 07 2019 - 23:20:50 CST