From 07c15b806a89b7efbb05e6b61fb93ed3bafc5f8f Mon Sep 17 00:00:00 2001 From: sjplimp Date: Fri, 26 Jun 2009 18:41:31 +0000 Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@2903 f3b2605a-c512-4ea7-a41b-209d697bcdaa --- doc/compute_temp_asphere.html | 33 ++++++++++++++++++--------------- doc/compute_temp_asphere.txt | 33 ++++++++++++++++++--------------- doc/compute_temp_sphere.html | 9 +++++++++ doc/compute_temp_sphere.txt | 9 +++++++++ 4 files changed, 54 insertions(+), 30 deletions(-) diff --git a/doc/compute_temp_asphere.html b/doc/compute_temp_asphere.html index cfcdc8ac89..e81cae8457 100644 --- a/doc/compute_temp_asphere.html +++ b/doc/compute_temp_asphere.html @@ -32,23 +32,26 @@ translational and rotational kinetic energy. This differs from the usual compute temp command, which assumes point particles with only translational kinetic energy.

-

For 3d aspherical particles, each has 3, 5, or 6 degrees of freedom (3 -translational, remainder rotational), depending on whether the -particle is spherical, uniaxial, or biaxial. This is determined by -the shape command. Uniaxial means two of its three shape -parameters are equal. Biaxial means all 3 shape parameters are -different. +

For 3d aspherical particles, each has 6 degrees of freedom (3 +translational, 3 rotational). For 2d aspherical particles, each has 3 +degrees of freedom (2 translational, 1 rotational).

-

For 2d aspherical particles, each has 3 or 4 degrees of freedom (3 -translational, remainder rotational), depending on whether the -particle is spherical, or biaxial. Biaxial means the x,y shape -parameters are unequal. +

IMPORTANT NOTE: This choice for degrees of freedom (dof) makes the +assumption that all aspherical particles in your model will freely +rotate, sampling all their rotational dof. It is possible to use a +combination of interaction potentials and fixes that induce no torque +or otherwise constrain some of all of your particles so that this is +not the case. Then there are less dof and you should use the +compute_modify extra command to adjust the dof +accordingly.

-

IMPORTANT NOTE: These degrees of freedom assume that the interaction -potential between degenerate aspherical particles does not impart -rotational motion to the extra degrees of freedom. E.g. the GayBerne -pair potential does not impart torque to spherical -particles, so they do not rotate. +

For example, an aspherical particle with all three of its +shape parameters the same is a sphere. If it does not +rotate, then it should have 3 dof instead of 6 in 3d (or 2 instead of +3 in 2d). A uniaxial aspherical particle has two of its three shape +parameters the same. If it does not rotate around the axis +perpendicular to its circular cross section, then it should have 5 dof +instead of 6 in 3d.

The translational kinetic energy is computed the same as is described by the compute temp command. The rotational diff --git a/doc/compute_temp_asphere.txt b/doc/compute_temp_asphere.txt index 590b10d21f..a8418f096f 100755 --- a/doc/compute_temp_asphere.txt +++ b/doc/compute_temp_asphere.txt @@ -29,23 +29,26 @@ translational and rotational kinetic energy. This differs from the usual "compute temp"_compute_temp.html command, which assumes point particles with only translational kinetic energy. -For 3d aspherical particles, each has 3, 5, or 6 degrees of freedom (3 -translational, remainder rotational), depending on whether the -particle is spherical, uniaxial, or biaxial. This is determined by -the "shape"_shape.html command. Uniaxial means two of its three shape -parameters are equal. Biaxial means all 3 shape parameters are -different. +For 3d aspherical particles, each has 6 degrees of freedom (3 +translational, 3 rotational). For 2d aspherical particles, each has 3 +degrees of freedom (2 translational, 1 rotational). -For 2d aspherical particles, each has 3 or 4 degrees of freedom (3 -translational, remainder rotational), depending on whether the -particle is spherical, or biaxial. Biaxial means the x,y shape -parameters are unequal. +IMPORTANT NOTE: This choice for degrees of freedom (dof) makes the +assumption that all aspherical particles in your model will freely +rotate, sampling all their rotational dof. It is possible to use a +combination of interaction potentials and fixes that induce no torque +or otherwise constrain some of all of your particles so that this is +not the case. Then there are less dof and you should use the +"compute_modify extra"_compute_modify.html command to adjust the dof +accordingly. -IMPORTANT NOTE: These degrees of freedom assume that the interaction -potential between degenerate aspherical particles does not impart -rotational motion to the extra degrees of freedom. E.g. the "GayBerne -pair potential"_pair_gayberne.html does not impart torque to spherical -particles, so they do not rotate. +For example, an aspherical particle with all three of its +"shape"_shape.html parameters the same is a sphere. If it does not +rotate, then it should have 3 dof instead of 6 in 3d (or 2 instead of +3 in 2d). A uniaxial aspherical particle has two of its three shape +parameters the same. If it does not rotate around the axis +perpendicular to its circular cross section, then it should have 5 dof +instead of 6 in 3d. The translational kinetic energy is computed the same as is described by the "compute temp"_compute_temp.html command. The rotational diff --git a/doc/compute_temp_sphere.html b/doc/compute_temp_sphere.html index af85c19995..ff4f23a96a 100644 --- a/doc/compute_temp_sphere.html +++ b/doc/compute_temp_sphere.html @@ -36,6 +36,15 @@ particles with only translational kinetic energy. translational, 3 rotational). For 2d spherical particles, each has 3 degrees of freedom (2 translational, 1 rotational).

+

IMPORTANT NOTE: This choice for degrees of freedom (dof) makes the +assumption that all spherical particles in your model will freely +rotate, sampling all their rotational dof. It is possible to use a +combination of interaction potentials and fixes that induce no torque +or otherwise constrain some of all of your particles so that this is +not the case. Then there are less dof and you should use the +compute_modify extra command to adjust the dof +accordingly. +

The translational kinetic energy is computed the same as is described by the compute temp command. The rotational kinetic energy is computed as 1/2 I w^2, where I is the moment of diff --git a/doc/compute_temp_sphere.txt b/doc/compute_temp_sphere.txt index 308e028e5e..945ed15d97 100755 --- a/doc/compute_temp_sphere.txt +++ b/doc/compute_temp_sphere.txt @@ -33,6 +33,15 @@ For 3d spherical particles, each has 6 degrees of freedom (3 translational, 3 rotational). For 2d spherical particles, each has 3 degrees of freedom (2 translational, 1 rotational). +IMPORTANT NOTE: This choice for degrees of freedom (dof) makes the +assumption that all spherical particles in your model will freely +rotate, sampling all their rotational dof. It is possible to use a +combination of interaction potentials and fixes that induce no torque +or otherwise constrain some of all of your particles so that this is +not the case. Then there are less dof and you should use the +"compute_modify extra"_compute_modify.html command to adjust the dof +accordingly. + The translational kinetic energy is computed the same as is described by the "compute temp"_compute_temp.html command. The rotational kinetic energy is computed as 1/2 I w^2, where I is the moment of