[gmx-users] Re: how to constrain the position of DPPC and water

[xiaoyi li]

Dear gmx users,

Thanks for Derrick, Anton, Peter and David that I wrote out my top file
and gro file and they works at last. 

My system is DPPC bilayer with water outside and two coumaryl molecules
in the middle. However, after run the MD, I find some DPPC molecules run
out of the bilayer and mixed with water. The high ordered arrangement of
DPPC bilayer has changed too much. But I want the DPPC and water to be
the environment and relatively fixed, and only coumaryls in the middle
can move freely. I will be appreciate if someone tell me how to achieve
this?


Thanks,

-- 
xiaoyi li <xiaoyi at xray.bmc.uu.se>