Hello gmx-users, I did create nice random mixture of lipids, EM was ok Epot=500. But after adding the water (by genbox) EM does not work. Fmax=10e+13 in 50 steps :) very nice one. Probably answer is very simple, if not i'll provide my *.mdp files. -- Best regards, Andrey mailto:golovin at genebee.msu.su