git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@7802 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2012-02-16 15:49:48 +00:00
parent 3ff9f1fa60
commit e546f9a54b
4 changed files with 48 additions and 10 deletions

View File

@ -51,6 +51,12 @@ E.g. 1/4 of the dihedral energy to each of the 4 atoms.
pairwise interactions between 1-4 atoms. The energy contribution of pairwise interactions between 1-4 atoms. The energy contribution of
these terms is included in the pair energy, not the dihedral energy. these terms is included in the pair energy, not the dihedral energy.
</P> </P>
<P>The KSpace contribution is calculated using the method in
<A HREF = "#Heyes">(Heyes)</A> for the Ewald method and a related method for PPPM,
as specified by the <A HREF = "kspace_style.html">kspace_style pppm</A> command.
For PPPM, the calcluation requires 1 extra FFT each timestep that
per-atom stress is calculated.
</P>
<P>As an example of per-atom potential energy compared to total potential <P>As an example of per-atom potential energy compared to total potential
energy, these lines in an input script should yield the same result energy, these lines in an input script should yield the same result
in the last 2 columns of thermo output: in the last 2 columns of thermo output:
@ -81,4 +87,10 @@ stress/atom</A>
</P> </P>
<P><B>Default:</B> none <P><B>Default:</B> none
</P> </P>
<HR>
<A NAME = "Heyes"></A>
<P><B>(Heyes)</B> Heyes, Phys Rev B 49, 755 (1994),
</P>
</HTML> </HTML>

View File

@ -48,6 +48,12 @@ The "dihedral_style charmm"_dihedral_charmm.html style calculates
pairwise interactions between 1-4 atoms. The energy contribution of pairwise interactions between 1-4 atoms. The energy contribution of
these terms is included in the pair energy, not the dihedral energy. these terms is included in the pair energy, not the dihedral energy.
The KSpace contribution is calculated using the method in
"(Heyes)"_#Heyes for the Ewald method and a related method for PPPM,
as specified by the "kspace_style pppm"_kspace_style.html command.
For PPPM, the calcluation requires 1 extra FFT each timestep that
per-atom stress is calculated.
As an example of per-atom potential energy compared to total potential As an example of per-atom potential energy compared to total potential
energy, these lines in an input script should yield the same result energy, these lines in an input script should yield the same result
in the last 2 columns of thermo output: in the last 2 columns of thermo output:
@ -77,3 +83,8 @@ The per-atom vector values will be in energy "units"_units.html.
stress/atom"_compute_stress_atom.html stress/atom"_compute_stress_atom.html
[Default:] none [Default:] none
:line
:link(Heyes)
[(Heyes)] Heyes, Phys Rev B 49, 755 (1994),

View File

@ -75,11 +75,13 @@ other atoms in the simulation, not just with other atoms in the group.
pairwise interactions between 1-4 atoms. The virial contribution of pairwise interactions between 1-4 atoms. The virial contribution of
these terms is included in the pair virial, not the dihedral virial. these terms is included in the pair virial, not the dihedral virial.
</P> </P>
<P>The KSpace contribution to the per-atom stress requires 6 extra FFTs <P>The KSpace contribution is calculated using the method in
each timestep that per-atom stress is calculated, if using the PPPM <A HREF = "#Heyes">(Heyes)</A> for the Ewald method and a related method for PPPM,
solver via the <A HREF = "kspace_style.html">kspace_style pppm</A> command. Thus it as specified by the <A HREF = "kspace_style.html">kspace_style pppm</A> command.
can significantly increase the cost of the PPPM calculation if it is For PPPM, the calcluation requires 6 extra FFTs each timestep that
needed on a large fraction of the simulation timesteps. per-atom stress is calculated. Thus it can significantly increase the
cost of the PPPM calculation if it is needed on a large fraction of
the simulation timesteps.
</P> </P>
<P>Note that as defined in the formula, per-atom stress is the negative <P>Note that as defined in the formula, per-atom stress is the negative
of the per-atom pressure tensor. It is also really a stress*volume of the per-atom pressure tensor. It is also really a stress*volume
@ -119,4 +121,10 @@ options.
</P> </P>
<P><B>Default:</B> none <P><B>Default:</B> none
</P> </P>
<HR>
<A NAME = "Heyes"></A>
<P><B>(Heyes)</B> Heyes, Phys Rev B 49, 755 (1994),
</P>
</HTML> </HTML>

View File

@ -72,11 +72,13 @@ The "dihedral_style charmm"_dihedral_charmm.html style calculates
pairwise interactions between 1-4 atoms. The virial contribution of pairwise interactions between 1-4 atoms. The virial contribution of
these terms is included in the pair virial, not the dihedral virial. these terms is included in the pair virial, not the dihedral virial.
The KSpace contribution to the per-atom stress requires 6 extra FFTs The KSpace contribution is calculated using the method in
each timestep that per-atom stress is calculated, if using the PPPM "(Heyes)"_#Heyes for the Ewald method and a related method for PPPM,
solver via the "kspace_style pppm"_kspace_style.html command. Thus it as specified by the "kspace_style pppm"_kspace_style.html command.
can significantly increase the cost of the PPPM calculation if it is For PPPM, the calcluation requires 6 extra FFTs each timestep that
needed on a large fraction of the simulation timesteps. per-atom stress is calculated. Thus it can significantly increase the
cost of the PPPM calculation if it is needed on a large fraction of
the simulation timesteps.
Note that as defined in the formula, per-atom stress is the negative Note that as defined in the formula, per-atom stress is the negative
of the per-atom pressure tensor. It is also really a stress*volume of the per-atom pressure tensor. It is also really a stress*volume
@ -115,3 +117,8 @@ The per-atom array values will be in pressure*volume
"compute pe"_compute_pe.html, "compute pressure"_compute_pressure.html "compute pe"_compute_pe.html, "compute pressure"_compute_pressure.html
[Default:] none [Default:] none
:line
:link(Heyes)
[(Heyes)] Heyes, Phys Rev B 49, 755 (1994),