[gmx-users] DPPC/DPPE/H2O simulation

[X.Periole]

On Tue, 01 Mar 2005 22:22:25 -0500
  Sukit Leekumjorn <leekumjo at vt.edu> wrote:
> Dear GMX Users,
> 
> This is my first time using Gromacs and I came across a 
>problem while running the simulation.
> 
> Right now I have a properly working DPPC/water system 
>and I am trying to modify it.  My task is to substitute 
>some of the DPPC with DPPE molecules (very much the same 
>in structure except CH3 is replaced by H on the amine 
>group).  I did the following:
> 1)    change the molecules CH3 to H in the .gro file
> 2)    add an H in the ff parameter so that all of the 
>parameters are listed
> 3)    add another line in ff...nb LJ of C6=0 and C12=0 
>for hydrogen
> 
I am prety sure the force field for DPPE existe. The only 
difference between those two lipids is the head groups. 
You actually just have to substitute the CH3 by H, as you 
did I guess and call them DPPE instead of DPPE the program 
should make the rest for you.

XAvier