[gmx-users] Re: [gmx-users] convert an itp from gmx to olps?

[nicolis@guideo.fr]

Thank you for the suggestions Erik. I reply after some time because we 
worked on other projects during this time.
Some more questions:

> That depends on how you created your itp file; if you haven't added any 
> explicit parameters (i.e. they are looked up based on the atom types) it 
> might suffice to:
> 
> 1. Add the hydrogens

OK

> 2. Change atom types to OPLS ones

Is there a special atom type for N in phenylamines (and phenyl C bound to N). 
The molecule is a derivative of diphenylamine.

> 3. Remove chiral-center improper dihedrals

Not a chiral molecule, so no problem.

> 4. Change proper dihedrals to type 3.
> 
> You might also want to change planar group impropers to OPLS dihedrals 
> with a periodicity of 2, but I can't imagine that will affect things too 
> much....

Well, actually I thought just use the improper definitions in!
 the 
=0
Affoplsaabon.itp

Thanks for the suggestions, I will post the topology when constructed,

Ioannis