Hello gmx-users! I am still struggling with the energy conservation in the system where a water droplet (consisting of rigid molecules) collides with a frozen structured surface. The total energy is well conserved at the beginning of NVE simulation when the droplet is approaching the surface and once again when the droplet is stabilized on the surface, but the drift or fluctuation in the total energy is observed between these extremes.
The total energy of the system (~300 000kJ/mol) decreases slightly (<100kJ/mol) at the collision and on non-wetting surfaces (water droplet wont intrude to the pores of the surface) part of the energy reverts quickly causing a sharp peak in the energy curve. This could indicate an integration error at the collision due to the large time step, but equal behavior is observed with the time steps of 2.0fs and 0.5fs. On the wetting surfaces (water droplet intrude to the pores of the surface) the center of mass motion of the droplet come to a stop at the collision as in the case of non-wetting surface and sharp decrease in the total energy is observed. However, now none of this energy is reverted and the total energy stabilize to this value until the water molecules starts to intrude to the pores of the surface. The total energy decrease slowly in conjuction with the slow sinking of the height of the center of mass of the water droplet until the bottom of the pores is reached. After the bottom of the pores is reached energy will stabilize to the corresponding value which is about 200-300kJ/mol lower than at the beginning. Decreasing the time step from 2.0fs to 0.5fs have no influence for the energy conservation and somehow the problem seems to be connected to water-surface interactions: on the wetting surfaces (more water-surface interactions) a drift is observed instead of a sharp peak of non-wetting surfaces (less water-surface interactions). Any ideas how I could achieve complete energy conservation? Thanks for your time and help, Janne _______________________________________________ gmx-users mailing list [email protected] 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
