[lammps-users] orientation

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21

Dear Steve,

Yes. I am constraining my ellipsoids to not rotate. They have only the translational 3 DOF each. When I deleted “command lines (dark lines as the following)”, temperature reachs the correct value in the result file.The fix npt is applied to only the translational degrees of freedom for the particles.Then Compute temp/asphere defines a computation that calculates the temperature of a group of aspherical particles, including a contribution from only translational kinetic energy.

I think the problem is solved.

Am I wrong?

Thanks in advance

…
shape 1 1 1 3
set group all quat 0 0 1 0

compute rot all temp/asphere
#group spheroid type 1
#variable dof equal count(spheroid)+2------->+2 is rotational DOF
#compute_modify rot extra ${dof}

fix 1 all npt 2.0 2.0 0.5 xyz 0.0 8.0 0.5
#compute_modify 1_temp extra ${dof}
…

02 Kasım 2009 16:50 tarihinde Steve Plimpton <sjplimp@…33…24…> yazdı:

22

I would use compute temp, not compute temp/asphere on
ellipsoids that are not rotating. And use that temp
with thermodyanmics and fix npt.

Steve

2009/11/2 ahmet yıldırım <[email protected]...>:

23

Dear Steve,

Firstly, Thanks for your helps,

Ok.I will use “compute rot all temp” instead of “compute rot all temp/asphere”(as the following).

You said “and use that temp with thermodynamics and fix npt”.I am sorry.I could not understand what you mean.

Thanks

…
shape 1 1 1 3
set group all quat 0 0 1 0

compute rot all temp
#group spheroid type 1
#variable dof equal count(spheroid)+2

#compute_modify rot extra ${dof}

fix 1 all npt 2.0 2.0 0.5 xyz 0.0 8.0 0.5
#compute_modify 1_temp extra ${dof}
…

03 Kasım 2009 17:15 tarihinde Steve Plimpton <sjplimp@…33…24…> yazdı:

24

If you define a compute foo temp all, then you can output it with
thermo (same as default, but also by thermo_modify temp), and
use it with fix npt/asphere via fix_modify temp. But you would
probably be better off to just use fix npt.

Steve

2009/11/3 ahmet yıldırım <[email protected]...>: