[gmx-users] CP atom type

Mark Abraham Mark.Abraham at anu.edu.au
Fri Feb 10 04:43:55 CET 2006

Rongliang Wu wrote:
> Hello gmx-users,
> 	the decane included has no charge for each atom, is it reasonable? 

What charge would you like for united-atom CH2 groups, so that the sum
for identical units is zero?

> what are the cp3 and cp2 type carbons? 

Terminal and non-terminal aliphatic carbons?

> what's the difference between CP3 and CH3?

Don't know, try finding the paper where they describe the development.
I'd guess the former is for (some kind of) lipid and the other isn't.

> is it for the CP type that lead to the zero charge for each atom?

No, that's intrinsic to the united-atom description for this type of
molecule. The CH3 all have zero too.

>     another error is the BEN in ffgmx.rtp, the charge group division is wrong.

Yeah it looks weird.

>     by the way, is the ffgmx forcefield recognized by magazines? 

I suggest find some papers that simulate systems similar to what you
want to do and see what they used, and find the ffgmx forcefield
development papers to see if it was intended for your sort of system.

> which gromos96 force field is best for long chain simulations?

Don't know.


More information about the gromacs.org_gmx-users mailing list