[gmx-users] Does gromacs use group-based charge groups in the PME method?

[Anton Feenstra]

S. W. Chiu wrote:
> Hi:
>   In the Gromacs package, the rtp files have group-based charge groups
> defined. When using the PME method, does Gromacs use these group-based
> charge groups in calculations of the electrosatic interaction in the
> real space and the fourier space? If so, will the electrostatic forces
> for some atoms be doubly counted since some charge groups may have atoms
> wihthin and outside the range of the real space cutoff?

No, charge groups are used in the neighboursearching only, i.e. the center
of the charge group is used to determine if the atoms of the group will be
inside or outside the cut-off. All interactions are calculated based on the
individial atomic charges.

-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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