[lammps-users] Bugs?! Wrong properties of liquid crystal

Dear all,

I modeled a liquid crystal with GB potential under reduced temperature 1.9. It should be random structure according to several published papers. But what I got is perfect ordering structure.

About one week ago, I sent my GB parameters to the mail list and validated these parameters. If the GB parameters are right, the control of pressure or temperature has bugs maybe. Does anyone have the similar opinion with me? Are there some information missed in kinetic energy calculation for temperature or in Virial for pressure? So I tried a series of pressures ( style xyz) and temperatures. Where these bugs are ? thanks a million.

I know of no errors in the GB virial or temperature in
the current version of LAMMPS.

Steve

2008/2/12 Kitty Ji <[email protected]>:

One thing you need to make sure of in your input script.
The temp and press reported by thermo will not include
rotational degrees of freedom by default. Thus they
could be off from what you expect.

You need to do something like:

compute myTemp all temp/asphere
thermo_modify temp myTemp

This will use a "temperature" that includes rotational
effects for both the temp and pressure reported by
thermodynamics.

You don't need to worry about it for NPT since
you are using fix npt/asphere and it manages temperature
internally.

Mike - can you verify these instructions are consistent
with what you do?

Steve