git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@9109 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2012-11-26 18:29:40 +00:00
parent a64357160f
commit 00d8960bb0
2 changed files with 87 additions and 25 deletions

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@ -32,11 +32,18 @@
<I>xyz</I> args = Nx Ny Nz
Nx,Ny,Nz = number of velocity bins in x,y,z dimensions
</PRE>
<LI>zero or more keyword/value pairs may be appended
<LI>keyword = <I>out</I>
<PRE> <I>out</I> value = <I>tensor</I> or <I>bin</I>
</PRE>
</UL>
<P><B>Examples:</B>
</P>
<PRE>compute myTemp flow temp/profile 1 1 1 x 10
compute myTemp flow temp/profile 1 1 1 x 10 out bin
compute myTemp flow temp/profile 0 1 1 xyz 20 20 20
</PRE>
<P><B>Description:</B>
@ -77,12 +84,17 @@ T, where KE = total kinetic energy of the group of atoms (sum of 1/2 m
v^2), dim = 2 or 3 = dimensionality of the simulation, N = number of
atoms in the group, k = Boltzmann constant, and T = temperature.
</P>
<P>A kinetic energy tensor, stored as a 6-element vector, is also
calculated by this compute for use in the computation of a pressure
tensor. The formula for the components of the tensor is the same as
the above formula, except that v^2 is replaced by vx*vy for the xy
component, etc. The 6 components of the vector are ordered xx, yy,
zz, xy, xz, yz.
<P>If the <I>out</I> keyword is used with a <I>tensor</I> value, which is the
default, a kinetic energy tensor, stored as a 6-element vector, is
also calculated by this compute for use in the computation of a
pressure tensor. The formula for the components of the tensor is the
same as the above formula, except that v^2 is replaced by vx*vy for
the xy component, etc. The 6 components of the vector are ordered xx,
yy, zz, xy, xz, yz.
</P>
<P>If the <I>out</I> keyword is used with a <I>bin</I> value, the count of atoms
and computed temperature for each bin are stored for output, as an
array of values, as described below.
</P>
<P>The number of atoms contributing to the temperature is assumed to be
constant for the duration of the run; use the <I>dynamic</I> option of the
@ -106,6 +118,12 @@ atoms that include these constraints will be computed correctly. If
needed, the subtracted degrees-of-freedom can be altered using the
<I>extra</I> option of the <A HREF = "compute_modify.html">compute_modify</A> command.
</P>
<P>IMPORTANT NOTE: When using the <I>out</I> keyword with a value of <I>bin</I>,
the calculated temperature for each bin does not include the
degrees-of-freedom adjustment described in the preceeding paragraph,
for fixes that constrain molecular motion. It does include the
adjustment due to the <I>extra</I> option, which is applied to each bin.
</P>
<P>See <A HREF = "Section_howto.html#howto_16">this howto section</A> of the manual for
a discussion of different ways to compute temperature and perform
thermostatting. Using this compute in conjunction with a
@ -114,18 +132,32 @@ profile-unbiased thermostat (PUT), as described in <A HREF = "#Evans">(Evans)</A
</P>
<P><B>Output info:</B>
</P>
<P>This compute calculates a global scalar (the temperature) and a global
vector of length 6 (KE tensor), which can be accessed by indices 1-6.
These values can be used by any command that uses global scalar or
vector values from a compute as input. See <A HREF = "Section_howto.html#howto_15">this
<P>This compute calculates a global scalar (the temperature). Depending
on the setting of the <I>out</I> keyword, it also calculates a global
vector or array. For <I>out</I> = <I>tensor</I>, it calculates a vector of
length 6 (KE tensor), which can be accessed by indices 1-6. For <I>out</I>
= <I>bin</I> it calculates a global array which has 2 columns and N rows,
where N is the number of bins. The first column contains the number
of atoms in that bin. The second contains the temperature of that
bin, calculated as described above. The ordering of rows in the array
is as follows. Bins in x vary fastest, then y, then z. Thus for a
10x10x10 3d array of bins, there will be 1000 rows. The bin with
indices ix,iy,iz = 2,3,4 would map to row M = (iz-1)*10*10 + (iy-1)*10
+ ix = 322, where the rows are numbered from 1 to 1000 and the bin
indices are numbered from 1 to 10 in each dimension.
</P>
<P>These values can be used by any command that uses global scalar or
vector or array values from a compute as input. See <A HREF = "Section_howto.html#howto_15">this
section</A> for an overview of LAMMPS output
options.
</P>
<P>The scalar value calculated by this compute is "intensive". The
vector values are "extensive".
vector values are "extensive". The array values are "intensive".
</P>
<P>The scalar value will be in temperature <A HREF = "units.html">units</A>. The
vector values will be in energy <A HREF = "units.html">units</A>.
vector values will be in energy <A HREF = "units.html">units</A>. The first column
of array values are counts; the values in the second column will be in
temperature <A HREF = "units.html">units</A>.
</P>
<P><B>Restrictions:</B>
</P>
@ -144,7 +176,7 @@ pressure</A>
</P>
<P><B>Default:</B>
</P>
<P>The option default is units = lattice.
<P>The option default is out = tensor.
</P>
<HR>

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@ -24,11 +24,16 @@ binstyle = {x} or {y} or {z} or {xy} or {yz} or {xz} or {xyz} :l
{xz} args = Nx Nz
{xyz} args = Nx Ny Nz
Nx,Ny,Nz = number of velocity bins in x,y,z dimensions :pre
zero or more keyword/value pairs may be appended :l
keyword = {out} :l
{out} value = {tensor} or {bin} :pre
:ule
[Examples:]
compute myTemp flow temp/profile 1 1 1 x 10
compute myTemp flow temp/profile 1 1 1 x 10 out bin
compute myTemp flow temp/profile 0 1 1 xyz 20 20 20 :pre
[Description:]
@ -69,12 +74,17 @@ T, where KE = total kinetic energy of the group of atoms (sum of 1/2 m
v^2), dim = 2 or 3 = dimensionality of the simulation, N = number of
atoms in the group, k = Boltzmann constant, and T = temperature.
A kinetic energy tensor, stored as a 6-element vector, is also
calculated by this compute for use in the computation of a pressure
tensor. The formula for the components of the tensor is the same as
the above formula, except that v^2 is replaced by vx*vy for the xy
component, etc. The 6 components of the vector are ordered xx, yy,
zz, xy, xz, yz.
If the {out} keyword is used with a {tensor} value, which is the
default, a kinetic energy tensor, stored as a 6-element vector, is
also calculated by this compute for use in the computation of a
pressure tensor. The formula for the components of the tensor is the
same as the above formula, except that v^2 is replaced by vx*vy for
the xy component, etc. The 6 components of the vector are ordered xx,
yy, zz, xy, xz, yz.
If the {out} keyword is used with a {bin} value, the count of atoms
and computed temperature for each bin are stored for output, as an
array of values, as described below.
The number of atoms contributing to the temperature is assumed to be
constant for the duration of the run; use the {dynamic} option of the
@ -98,6 +108,12 @@ atoms that include these constraints will be computed correctly. If
needed, the subtracted degrees-of-freedom can be altered using the
{extra} option of the "compute_modify"_compute_modify.html command.
IMPORTANT NOTE: When using the {out} keyword with a value of {bin},
the calculated temperature for each bin does not include the
degrees-of-freedom adjustment described in the preceeding paragraph,
for fixes that constrain molecular motion. It does include the
adjustment due to the {extra} option, which is applied to each bin.
See "this howto section"_Section_howto.html#howto_16 of the manual for
a discussion of different ways to compute temperature and perform
thermostatting. Using this compute in conjunction with a
@ -106,18 +122,32 @@ profile-unbiased thermostat (PUT), as described in "(Evans)"_#Evans.
[Output info:]
This compute calculates a global scalar (the temperature) and a global
vector of length 6 (KE tensor), which can be accessed by indices 1-6.
This compute calculates a global scalar (the temperature). Depending
on the setting of the {out} keyword, it also calculates a global
vector or array. For {out} = {tensor}, it calculates a vector of
length 6 (KE tensor), which can be accessed by indices 1-6. For {out}
= {bin} it calculates a global array which has 2 columns and N rows,
where N is the number of bins. The first column contains the number
of atoms in that bin. The second contains the temperature of that
bin, calculated as described above. The ordering of rows in the array
is as follows. Bins in x vary fastest, then y, then z. Thus for a
10x10x10 3d array of bins, there will be 1000 rows. The bin with
indices ix,iy,iz = 2,3,4 would map to row M = (iz-1)*10*10 + (iy-1)*10
+ ix = 322, where the rows are numbered from 1 to 1000 and the bin
indices are numbered from 1 to 10 in each dimension.
These values can be used by any command that uses global scalar or
vector values from a compute as input. See "this
vector or array values from a compute as input. See "this
section"_Section_howto.html#howto_15 for an overview of LAMMPS output
options.
The scalar value calculated by this compute is "intensive". The
vector values are "extensive".
vector values are "extensive". The array values are "intensive".
The scalar value will be in temperature "units"_units.html. The
vector values will be in energy "units"_units.html.
vector values will be in energy "units"_units.html. The first column
of array values are counts; the values in the second column will be in
temperature "units"_units.html.
[Restrictions:]
@ -136,7 +166,7 @@ pressure"_compute_pressure.html
[Default:]
The option default is units = lattice.
The option default is out = tensor.
:line