ICODE-ADC/lammps
4
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@191 f3b2605a-c512-4ea7-a41b-209d697bcdaa

Browse Source
This commit is contained in:
pscrozi
2006-12-13 16:50:24 +00:00
parent e5d19d4a9e
commit 869e9ba92e
3 changed files with 15 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
doc/fix_rigid.html
View File

@ -72,7 +72,11 @@ rigid fixes to be defined, but it is more expensive.
temperature and pressure computations. Similary, the rigid body
contribution to the pressure virial is also accounted for. The latter
is only correct if forces within the bodies have been turned off, and
there is only a single fix rigid defined.
there is only a single fix rigid defined. For each linear rigid body
of three or more atoms, one degree-of-freedom must be added using a
<A HREF = "temp_modify.html">temp_modify</A> command (i.e. for a simulation of 10
such rigid bodies, use "temp_modify mine extra -7", where 3 is the
default setting and -10 degrees-of-freedom are subtracted).
</P>
<P>Note that this fix uses constant-energy integration, so you need to
impose additional constraints to control the temperature of an

6
doc/fix_rigid.txt
View File

@ -65,7 +65,11 @@ The degrees-of-freedom removed by rigid bodies are accounted for in
temperature and pressure computations. Similary, the rigid body
contribution to the pressure virial is also accounted for. The latter
is only correct if forces within the bodies have been turned off, and
there is only a single fix rigid defined.
there is only a single fix rigid defined. For each linear rigid body
of three or more atoms, one degree-of-freedom must be added using a
"temp_modify"_temp_modify.html command (i.e. for a simulation of 10
such rigid bodies, use "temp_modify mine extra -7", where 3 is the
default setting and -10 degrees-of-freedom are subtracted).
Note that this fix uses constant-energy integration, so you need to
impose additional constraints to control the temperature of an

7
src/fix_rigid.cpp
View File

@ -832,11 +832,14 @@ int FixRigid::dof(int igroup)
int *nall = new int[nbody];
MPI_Allreduce(ncount,nall,nbody,MPI_INT,MPI_SUM,world);
// remove 3N - 6 dof for each rigid body if at least 2 atoms are in igroup
// remove 3N - 6 dof for each rigid body if more than 2 atoms are in igroup
// remove 3N - 5 dof for each diatomic rigid body
int n = 0;
for (int ibody = 0; ibody < nbody; ibody++)
for (int ibody = 0; ibody < nbody; ibody++) {
if (nall[ibody] > 2) n += 3*nall[ibody] - 6;
else if (nall[ibody] == 2) n++;
}
delete [] ncount;
delete [] nall;