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[lammps-users] SRD energy calculations
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[lammps-users] SRD energy calculations

From: John Smith <johnson21smith@...24...>
Date: Mon, 12 Jun 2017 18:31:29 -0500


In the examples given under SRD, the calculation of potential energy for big particles is given as

variable pebig equal pe*atoms/count(big)

Here, do 'atoms' stand for the total number of atoms in the system? If yes, is this more of an average value of the PE of group big? Isn't there a way to get the pe of a certain group?

My other question is, I am calculating the vacf and mean square displacement as well using the fixes specifically for group big. Do I need to do this averaging for that as well? This is what I mean:

compute msd all msd
variable msdbig equal msd*atoms/count(big)

or can I just calculate that by doing the following:

compute msd big msd