From fd7945cabc5c6e3a8b38a89c9aba2df469bb6d91 Mon Sep 17 00:00:00 2001 From: sjplimp Date: Thu, 2 Jul 2009 15:09:14 +0000 Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@2947 f3b2605a-c512-4ea7-a41b-209d697bcdaa --- doc/fix_rigid.html | 24 ++++++++---------------- doc/fix_rigid.txt | 24 ++++++++---------------- 2 files changed, 16 insertions(+), 32 deletions(-) diff --git a/doc/fix_rigid.html b/doc/fix_rigid.html index 2a4d24d8d8..c586462f07 100644 --- a/doc/fix_rigid.html +++ b/doc/fix_rigid.html @@ -171,23 +171,15 @@ degrees-of-freedom removed by each rigid body are accounted for in the temperature (and pressure) computation, but only if the temperature group includes all the particles in a particular rigid body.

-

For rigid bodies consisting of point particles, a 3d body has 6 -degrees of freedom (3 translational, 3 rotational), except for a dimer -which only has 5. A 2d body has 3 degrees of freedom (2 -translational, 1 rotational). +

A 3d rigid body has 6 degrees of freedom (3 translational, 3 +rotational), except for a collection of point particles lying on a +straight line, which has only 5, e.g a dimer. A 2d rigid body has 3 +degrees of freedom (2 translational, 1 rotational).

-

For rigid bodies containing one or more finite-size particles, a 3d -body has 6 degrees of freedom, while a 2d body has 3. -

-

IMPORTANT NOTE: A "linear rigid body" is one consisting of 3 or more -point particles in a straight line. Linear rigid bodies in 3d have 5 -degrees of freedom (like a dimer) instead of 6, but LAMMPS will not -detect this. Thus if your model contains linear rigid bodies you -should use the compute_modify command to -subtract an additional degree of freedom for each one. You may also -wish to explicitly subtract additional degrees-of-freedom if you use -the force and torque keywords to eliminate certain motions of the -rigid body, as LAMMPS does not do this automatically. +

IMPORTANT NOTE: You may wish to explicitly subtract additional +degrees-of-freedom if you use the force and torque keywords to +eliminate certain motions of one or more rigid bodies, as LAMMPS does +not do this automatically.

The rigid body contribution to the pressure of the system (virial) is also accounted for by this fix. diff --git a/doc/fix_rigid.txt b/doc/fix_rigid.txt index dfcea35a17..2f4378b6fb 100644 --- a/doc/fix_rigid.txt +++ b/doc/fix_rigid.txt @@ -162,23 +162,15 @@ degrees-of-freedom removed by each rigid body are accounted for in the temperature (and pressure) computation, but only if the temperature group includes all the particles in a particular rigid body. -For rigid bodies consisting of point particles, a 3d body has 6 -degrees of freedom (3 translational, 3 rotational), except for a dimer -which only has 5. A 2d body has 3 degrees of freedom (2 -translational, 1 rotational). +A 3d rigid body has 6 degrees of freedom (3 translational, 3 +rotational), except for a collection of point particles lying on a +straight line, which has only 5, e.g a dimer. A 2d rigid body has 3 +degrees of freedom (2 translational, 1 rotational). -For rigid bodies containing one or more finite-size particles, a 3d -body has 6 degrees of freedom, while a 2d body has 3. - -IMPORTANT NOTE: A "linear rigid body" is one consisting of 3 or more -point particles in a straight line. Linear rigid bodies in 3d have 5 -degrees of freedom (like a dimer) instead of 6, but LAMMPS will not -detect this. Thus if your model contains linear rigid bodies you -should use the "compute_modify"_compute_modify.html command to -subtract an additional degree of freedom for each one. You may also -wish to explicitly subtract additional degrees-of-freedom if you use -the {force} and {torque} keywords to eliminate certain motions of the -rigid body, as LAMMPS does not do this automatically. +IMPORTANT NOTE: You may wish to explicitly subtract additional +degrees-of-freedom if you use the {force} and {torque} keywords to +eliminate certain motions of one or more rigid bodies, as LAMMPS does +not do this automatically. The rigid body contribution to the pressure of the system (virial) is also accounted for by this fix.