[gmx-users] Restrain lipid in a bilayer

[Li, Hualin]

Dear all,

     I am simulating a system with a mix-lipid membrane, say lipid A (10%, in the upper layer only) and lipid B (90%, in both upper and lower layer). I want to restrain the lipid A in a certain area in the upper leaflet (It is still moving, but can not escape from a circle). Is there any quick way other than modifying the pull code in GROMACS to do it please (The painful way is to apply a potential in the pull module, which seems to be too expensive)?

     Thanks in advance.

Regards,
Hualin