Mark Abraham wrote: > Hi, Mark > Thank you very much to your reply. I cannot undersand some points in > your reply. How to compute the volume that will lead to this pressure > when the system is equilibrated?
As I said last time, "Trial and error might be the best approach". You can make a guess in the following way. The total volume is the volume of the solution and the volume of the vapor. For a given number of vapor atoms at known temperature and pressure you can use the ideal gas law to find the gas volume. For a given amount of solution you can determine the volume from the density. This lets you choose V as as function of n - though how you choose a partition of n over the two phases is your problem! > in addition, do you mean the sysytem is > sandwich box or the cubic box? I didn't mention a box, and under PBC whatever distinction you're trying to draw is probably irrelevant. Mark > looking forward to your advice. Thank you very much. > Best wishes. > > > Beibei > > beibei wrote: >> Hi all, >> I want to simulate the liquid-vapor interface of I lithium >> bromide solution at 303K and 0.008bar. First I put the solution to a >> cubic box and used NPT ensemble to simulate. Then, I enlarged the box > to >> form two liquid-vapor interface,and used NVT ensemble, but the > pressure >> is not 0.008 bar. > > You need to determine a volume that will lead to this pressure when the > system is equilibrated. Then you need to measure for long enough to get > a meaningful average pressure. Trial and error might be the most > effective approach. Best of luck! > >> If I used NPT emsemble in the second step, the box >> becomes smaller with the run time. > > Of course... you won't get phase separation at equilibrium in NPT > unless > you happen to be at a critical point. Think about heating and cooling a > closed and open beaker of real water. > >> I want to know how to do when I >> want to simulate the liquid-vapor interface of a solution at a low > pressure. > > ------------------------------------------------------------------------ > 雅虎邮箱，您的终生邮箱！ <http://cn.mail.yahoo.com/> > _______________________________________________ > 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 > _______________________________________________ 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
