Velocity Create Error during Setup

Hi,

I have a mobile group and I am try to use the velocity command to create the initial with the temperature specified . I continue to get the following error.

ERROR: Attempting to rescale a 0.0 temperature (…/velocity.cpp:668)

When I looked into this error it says that it usually occurs when trying to rescale for a zero temperature. But I am not rescaling because I am using “create” style. Here is the following syntax for my input file.

group mof5 id 1 2 3 4 5 6 7

group methane id 8

fix 1 methane nvt temp 300 300 100

velocity methane create 300.0 49264

I am rather new to lammps, but from the manual “velocity groupid create temp seed” will create an initial distribution of velocity for that group at the specified temperature. The mof5 is a crystalline framework in which I am not relaxing or moving the atoms. This command works for pure methane without the framework. Is there something that I have done incorrect in translating the syntax. Please let me know if there is more information needed. Thank you in advance for you help.

Bests,

Velencia Witherspoon

2014-12-04 19:08 GMT+01:00 Velencia Witherspoon <[email protected]>
:

Hi,

I have a mobile group and I am try to use the velocity command to create
the initial with the temperature specified . I continue to get the
following error.

ERROR: Attempting to rescale a 0.0 temperature (../velocity.cpp:668)

When I looked into this error it says that it usually occurs when trying
to rescale for a zero temperature. But I am not rescaling because I am
using "create" style. Here is the following syntax for my input file.

If new velocities are created, they are random/independent for every atom
and have to be rescaled in order to ensure the total temperature is the
desired one, so you're still rescaling "under the hood".

Are you sure the "methane" group actually contains any atoms? Because in
that case, its temperature will certainly be zero (you can check this from
the screen output were you'll see some line reading "* atoms in group XXX").

Kristof

2014-12-06 9:54 GMT+01:00 Kristof Bal <[email protected]>:

2014-12-04 19:08 GMT+01:00 Velencia Witherspoon <
[email protected]>:

Hi,

I have a mobile group and I am try to use the velocity command to create
the initial with the temperature specified . I continue to get the
following error.

ERROR: Attempting to rescale a 0.0 temperature (../velocity.cpp:668)

When I looked into this error it says that it usually occurs when trying
to rescale for a zero temperature. But I am not rescaling because I am
using "create" style. Here is the following syntax for my input file.

If new velocities are created, they are random/independent for every atom
and have to be rescaled in order to ensure the total temperature is the
desired one, so you're still rescaling "under the hood".

Are you sure the "methane" group actually contains any atoms? Because in
that case, its temperature will certainly be zero (you can check this from
the screen output were you'll see some line reading "* atoms in group XXX").

I mean of course "if not, its temperature (...)". Sorry.