PDF file of the entire manual, generated by htmldoc
+IMPORTANT NOTE: If you are reading these HTML doc pages on the LAMMPS +WWW site, then they describe the most current, fully-patched version +of LAMMPS, which has changed after the date listed above. These +additions are described on this +page. If you are reading these +HTML doc pages from the doc directory of the tarball you downloaded, +then they will describe that tarball, whether it was the original +version for the date listed above, or an upgraded tarball including +features up to the date you downloaded it, again as described on this +page. When the tarball unpacks, it +will contain the date that corresponds to which version you +downloaded. The PDF file described above is not regenerated for every +patch, so it always corresponds to the original version with the date +listed above. +
IMPORTANT NOTE: This fix is overkill if you just want to hold group of +atoms stationary of have them move with a constant velocity. A +simpler way to hold atoms stationary is to not include those atoms in +your time integration fix. E.g. use "fix 1 mobile nve" instead of +"fix 1 all nve", where "mobile" is the group of atoms that you want to +move. You can move atoms with a constant velocity by assigning them +an initial velocity (via the velocity command), +setting the force on them to 0.0 (via the fix +setforce command), and integrating them as usual +(e.g. via the fix nve command).
IMPORTANT NOTE: This fix updates the positions and velocities of the rigid atoms with a constant-energy time integration, so you should not @@ -195,17 +204,6 @@ boundary, the input data file must define the image flags for each atom correctly, so that LAMMPS can "unwrap" the atoms into a valid rigid body.
-This fix is overkill if you just want to hold group of atoms -stationary of have them move with a constant velocity. A simpler way -to hold atoms stationary is to not include those atoms in your time -integration fix. E.g. use "fix 1 mobile nve" instead of "fix 1 all -nve", where "mobile" is the group of atoms that you want to move. You -can move atoms with a constant velocity by assigning them an initial -velocity (via the velocity command), setting the force -on them to 0.0 (via the fix setforce command), and -integrating them as usual (e.g. via the fix nve -command). -
Related commands:
delete_bonds, neigh_modify diff --git a/doc/fix_rigid.txt b/doc/fix_rigid.txt index b9cc5ebe09..991edad811 100644 --- a/doc/fix_rigid.txt +++ b/doc/fix_rigid.txt @@ -47,9 +47,18 @@ means that each timestep the total force and torque on each rigid body is computed and the coordinates and velocities of the atoms in each body are updated so that they move as a rigid body. This can be useful for freezing one or more portions of a large biomolecule, or -for simulating a system of colloidal particles. See the Restrictions -section if you simply want to hold a group of atoms motionless or have -them move with constant velocity. +for simulating a system of colloidal particles. + +IMPORTANT NOTE: This fix is overkill if you just want to hold group of +atoms stationary of have them move with a constant velocity. A +simpler way to hold atoms stationary is to not include those atoms in +your time integration fix. E.g. use "fix 1 mobile nve" instead of +"fix 1 all nve", where "mobile" is the group of atoms that you want to +move. You can move atoms with a constant velocity by assigning them +an initial velocity (via the "velocity"_velocity.html command), +setting the force on them to 0.0 (via the "fix +setforce"_fix_setforce.html command), and integrating them as usual +(e.g. via the "fix nve"_fix_nve.html command). IMPORTANT NOTE: This fix updates the positions and velocities of the rigid atoms with a constant-energy time integration, so you should not @@ -186,17 +195,6 @@ boundary, the input data file must define the image flags for each atom correctly, so that LAMMPS can "unwrap" the atoms into a valid rigid body. -This fix is overkill if you just want to hold group of atoms -stationary of have them move with a constant velocity. A simpler way -to hold atoms stationary is to not include those atoms in your time -integration fix. E.g. use "fix 1 mobile nve" instead of "fix 1 all -nve", where "mobile" is the group of atoms that you want to move. You -can move atoms with a constant velocity by assigning them an initial -velocity (via the "velocity"_velocity.html command), setting the force -on them to 0.0 (via the "fix setforce"_fix_setforce.html command), and -integrating them as usual (e.g. via the "fix nve"_fix_nve.html -command). - [Related commands:] "delete_bonds"_delete_bonds.html, "neigh_modify"_neigh_modify.html