[gmx-users] SR coulomb and LR Coulomb

[Erik Lindahl]

Hi,

On Mar 30, 2006, at 1:41 PM, Hector Martinez-Seara Monne wrote:

> Dear Gromacs users,
>
> I have what maybe is a silly question. I'm Using PME to perform my  
> calculations in bilayers and I have a set rcoulomb=1.0. What is the  
> SR coulomb and LR Coulomb energy in the log file? Can I say that LR  
> is the coulomb energy contribution of PME and SR is coulomb energy  
> contribution due to coulomb pairs interactions inside rcoulomb?

Almost - SR is the direct space coulomb interaction. This is not the  
same as the full interaction inside the cutoff, since the PME  
algorithm gradually switches off direct space interaction from r=0 to  
the cutoff, and treats the rest in reciprocal space.

Cheers,

Erik