[gmx-users] the force field of GROMOS96

[jiqing]

Hi: 
every one!

 In the GROMOS96 source file there is a file  named as ffG53a6nb.itp that relate to nonbond interaction parameters . one found 3 items:
1.[ atomtypes ]
2.[ nonbond_params ]
3.[ pairtypes ]

The unit 'CH2' both parameterized in 1. and 2.

Since the GMX have already used combination rule whether an arithmetical or geometrical averaged, why there is the parameters in above 2 items ? 

And more important is the values of these parameter is different ! Which one is the real parameter for simulation?

Thank in advance
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20060307/63a5a897/attachment.html>