git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@2790 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp
2009-04-30 16:53:04 +00:00
parent bbd7007b2e
commit 55ecf78cdc
4 changed files with 30 additions and 6 deletions

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@ -68,7 +68,8 @@ command for a discussion of the geometry of tilted boxes in LAMMPS.
are both in the compute group and in the same spatial bin is summed to are both in the compute group and in the same spatial bin is summed to
compute an average velocity for the bin. This bias velocity is then compute an average velocity for the bin. This bias velocity is then
subtracted from the velocities of individual atoms in the bin to yield subtracted from the velocities of individual atoms in the bin to yield
a thermal velocity. a thermal velocity for each atom. Note that if there is only one
atom in the bin, it's thermal velocity will thus be 0.0.
</P> </P>
<P>After the spatially-averaged velocity field has been subtracted from <P>After the spatially-averaged velocity field has been subtracted from
each atom, the temperature is calculated by the formula KE = dim/2 N k each atom, the temperature is calculated by the formula KE = dim/2 N k
@ -106,8 +107,8 @@ needed, the subtracted degrees-of-freedom can be altered using the
<P>See <A HREF = "Section_howto.html#4_16">this howto section</A> of the manual for a <P>See <A HREF = "Section_howto.html#4_16">this howto section</A> of the manual for a
discussion of different ways to compute temperature and perform discussion of different ways to compute temperature and perform
thermostatting. Using this compute in conjunction with a thermostatting. Using this compute in conjunction with a
thermostatting fix will effectively implement a PUT, as described in thermostatting fix, as explained there, will effectively implement a
<A HREF = "#Evans">(Evans)</A>. profile-unbiased thermostat (PUT), as described in <A HREF = "#Evans">(Evans)</A>.
</P> </P>
<P><B>Output info:</B> <P><B>Output info:</B>
</P> </P>

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@ -60,7 +60,8 @@ When a temperature is computed, the velocity for the set of atoms that
are both in the compute group and in the same spatial bin is summed to are both in the compute group and in the same spatial bin is summed to
compute an average velocity for the bin. This bias velocity is then compute an average velocity for the bin. This bias velocity is then
subtracted from the velocities of individual atoms in the bin to yield subtracted from the velocities of individual atoms in the bin to yield
a thermal velocity. a thermal velocity for each atom. Note that if there is only one
atom in the bin, it's thermal velocity will thus be 0.0.
After the spatially-averaged velocity field has been subtracted from After the spatially-averaged velocity field has been subtracted from
each atom, the temperature is calculated by the formula KE = dim/2 N k each atom, the temperature is calculated by the formula KE = dim/2 N k
@ -98,8 +99,8 @@ needed, the subtracted degrees-of-freedom can be altered using the
See "this howto section"_Section_howto.html#4_16 of the manual for a See "this howto section"_Section_howto.html#4_16 of the manual for a
discussion of different ways to compute temperature and perform discussion of different ways to compute temperature and perform
thermostatting. Using this compute in conjunction with a thermostatting. Using this compute in conjunction with a
thermostatting fix will effectively implement a PUT, as described in thermostatting fix, as explained there, will effectively implement a
"(Evans)"_#Evans. profile-unbiased thermostat (PUT), as described in "(Evans)"_#Evans.
[Output info:] [Output info:]

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@ -133,6 +133,17 @@ could potentially overflow the list. This threshold is set by the
<I>one</I> value which tells LAMMPS the maximum number of neighbor's one <I>one</I> value which tells LAMMPS the maximum number of neighbor's one
atom can have. atom can have.
</P> </P>
<P>IMPORTANT NOTE: LAMMPS can crash without an error message if the
number of neighbors for a single particle is larger than the <I>page</I>
setting, which means it is much, much larger than the <I>one</I> setting.
This is because LAMMPS doesn't error check these limits for every
pairwise interaction (too costly), but only after all the particle's
neighbors have been found. This problem usually means something is
very wrong with the way you've setup your problem (particle spacing,
cutoff length, neighbor skin distance, etc). If you really expect
that many neighbors per particle, then boost the <I>one</I> and <I>page</I>
settings accordingly.
</P>
<P>The <I>binsize</I> option allows you to specify what size of bins will be <P>The <I>binsize</I> option allows you to specify what size of bins will be
used in neighbor list construction to sort and find neighboring atoms. used in neighbor list construction to sort and find neighboring atoms.
By default, for <A HREF = "neighbor.html">neighbor style bin</A>, LAMMPS uses bins By default, for <A HREF = "neighbor.html">neighbor style bin</A>, LAMMPS uses bins

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@ -128,6 +128,17 @@ could potentially overflow the list. This threshold is set by the
{one} value which tells LAMMPS the maximum number of neighbor's one {one} value which tells LAMMPS the maximum number of neighbor's one
atom can have. atom can have.
IMPORTANT NOTE: LAMMPS can crash without an error message if the
number of neighbors for a single particle is larger than the {page}
setting, which means it is much, much larger than the {one} setting.
This is because LAMMPS doesn't error check these limits for every
pairwise interaction (too costly), but only after all the particle's
neighbors have been found. This problem usually means something is
very wrong with the way you've setup your problem (particle spacing,
cutoff length, neighbor skin distance, etc). If you really expect
that many neighbors per particle, then boost the {one} and {page}
settings accordingly.
The {binsize} option allows you to specify what size of bins will be The {binsize} option allows you to specify what size of bins will be
used in neighbor list construction to sort and find neighboring atoms. used in neighbor list construction to sort and find neighboring atoms.
By default, for "neighbor style bin"_neighbor.html, LAMMPS uses bins By default, for "neighbor style bin"_neighbor.html, LAMMPS uses bins