[gmx-developers] Fwd: User defined potential

[mustafa toprakci]

Dear Sir,
I would like to repost my message as I subscribed to the mailing list.

Best wishes
Mustafa


>Date: Sun, 14 Apr 2002 10:25:06 +0300
>To: gmx-developers at gromacs.org
>From: Mustafa Toprakçý <mtoprakci at ttnet.net.tr>
>Subject: User defined potential
>
>>Dear Developers,
>>I would like to add an extra repulsive potential to non bonded terms in 
>>Gromacs. In booklet there are two choices for non bonded potetials; LJ 
>>and Buckingham. My potential will be a half harmonic function such as,
>>
>>  V(r) = 1/2 k (r - ro)^2
>>
>>where k= 1000 kJ mol-1 nm-1
>>and ro = 0.4 nm.
>>
>>how can I add this function to the non bonded force fiald? There are 
>>coulombtype and vdwtype options in the mdp file but the vdwype consists 
>>of LJ and Bkh. But my function is of harmonic type
>>so I can not use 'user' option here for vdwtype. In previous discussions, 
>>it seems this needs source code edition. I will be glad if you show a way 
>>for doing this.
>>
>>  Regards,
>>Mustafa Toprakçý