Hello, I am simulating a lipid bilayer system under a shear stress, in which I am interested in looking at the surface tension. I have done a number of simulations in an NPT ensemble using semiisotropic Berendsen pressure coupling. For a system such as this, I am wondering what would be an optimal tau_p because I seem to be getting slightly different results dependent on the value I choose. For example, a 3ns simulation using a tau_p of 0.5 I get a surface tension of 30 dynes/cm and using a tau_p of 5.0 I get a surface tension of 25 dynes/cm. Is this difference negligible? I have looked into this a bit, and I have seen a number of publications in which people have used Berendsen pressure coupling in a lipid bilayer system with a coupling constant of 0.5 or 1.0ps. However, in the mailing list, there are some posts in which it is recommended that one use a tau_p of 5.0ps to 10.0ps due to semiisotropic coupling not having the averaging effect of isotropic coupling and using a small coupling time can add excessive noise to the system. Therefore, is it more reliable when simulating a lipid bilayer system to use a short tau_p ~0.5ps or a longer tau_p ~ 5.0ps?
Thank you, Mike Tomasini _______________________________________________ gmx-users mailing list gmx-users@gromacs.org http://www.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to [EMAIL PROTECTED] Can't post? Read http://www.gromacs.org/mailing_lists/users.php