[gmx-users] ffoplsaa and sigma/epsilon values

[Anton Feenstra]

Dallas Warren wrote:

> Derrick,
> 
>> i am right now attempting to edit the ffolpsaa forcefields non-bonded
>> parameters to add in a new molecule, specifically a lipid. i am running
>> gromacs v.3.1.4 and have looked through the manual to find out ways to
>> calculate  values, to of which i have yet to find something solid. i have
>> come close w/ section 5.3.3, but it has yet to answer all my 
>> questions. if
> 
> There are some discussions on the list on this, I am pretty sure there 
> should be a couple of emails that explicitly state the steps you need to 
> follow to perform the fit.  Basically you need to iterate the 
> non-bonding parameters to fit vapour pressure and density.

Important point is to adhere to the 'philosophies' used to derive the OPLS
forcefield. You should be able to find this in the relevant publications.


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
|(   |   )| | | De Boelelaan 1083 - 1081 HV Amsterdam - Netherlands   |
| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610           |
|             | Feenstra at chem.vu.nl - www.chem.vu.nl/~feenstra/       |
|             | "If You See Me Getting High, Knock Me Down"           |
|             | (Red Hot Chili Peppers)                               |
|_____________|_______________________________________________________|