[gmx-users] TIP3P versus SPC?

[Alan Wilter Sousa da Silva]

Hi Michael,

	I always want to do something like that so, if you allowed me, I
would like to suggest you testing also SPCE water.

	That would be very appreciated.

	Thanks in advance.

Cheers

On Mon, 17 Feb 2003, Michael Shirts wrote:

>
> Hi, all - I was just wondering about the differences of implementation of
> TIP3P and SPC in GROMACS.  I get a couple of odd things - below are outputs of
> g_energy from two simulations, identical conditions except that one has TIP3P
> and the other has SPC.  PME, rlist = rcoulomb = 1.15, Switched VdW 0.9-1.1,
> dispersion correction, 900 molecules, Nose-Hoover, Parrinello-Rahman.
>
> The densities remain close to the experimental values, but the coulombic
> energy for TIP3P is 20x that of SPC. Do you have any idea why this is the
> case?  It just seems rather odd that this differece in coulombic energy should
> exist without there being other large differences in other properties. . .

-----------------------
Alan Wilter S. da Silva
-----------------------
 Laboratório de Física Biológica
  Instituto de Biofísica Carlos Chagas Filho
   Universidade do Brasil/UFRJ
    Rio de Janeiro, Brasil