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@15372 f3b2605a-c512-4ea7-a41b-209d697bcdaa

Browse Source
This commit is contained in:
sjplimp
2016-07-27 14:13:02 +00:00
parent ee24be38cb
commit ef6ff80366
5 changed files with 69 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
doc/html/_sources/fix_nh.txt
View File

@ -76,7 +76,9 @@ Syntax
*flip* value = *yes* or *no* = allow or disallow box flips when it becomes highly skewed
*fixedpoint* values = x y z
x,y,z = perform barostat dilation/contraction around this point (distance units)
*update* value = *dipole* update dipole orientation (only for sphere variants)
*update* value = *dipole* or *dipole/dlm*
dipole = update dipole orientation (only for sphere variants)
dipole/dlm = use DLM integrator to update dipole orientation (only for sphere variants)
@ -376,6 +378,13 @@ during the time integration. This option should be used for models
where a dipole moment is assigned to finite-size particles,
e.g. spheroids via use of the :doc:`atom_style hybrid sphere dipole <atom_style>` command.
The default dipole orientation integrator can be changed the
Dullweber-Leimkuhler-McLachlan integration scheme
:ref:`(Dullweber) <nh-Dullweber>` when using *update* with the value
*dipole/dlm*\ . This integrator is symplectic and time-reversible,
giving better energy conservation and allows slightly longer timesteps
at only a small additional computational cost.
----------
@ -479,7 +488,7 @@ thermal degrees of freedom, and the bias is added back in.
----------
These fixes can be used with either the *verlet* or *respa*
These fixes can be used with either the *verlet* or *respa*
:doc:`integrators <run_style>`. When using one of the barostat fixes
with *respa*\ , LAMMPS uses an integrator constructed
according to the following factorization of the Liouville propagator
@ -505,7 +514,7 @@ of the underlying non-Hamiltonian equations of motion.
up to machine precision under NVT dynamics. Under NPT dynamics,
for a system with zero initial total linear momentum, the total
momentum fluctuates close to zero. It may occasionally undergo brief
excursions to non-negligible values, before returning close to zero.
excursions to non-negligible values, before returning close to zero.
Over long simulations, this has the effect of causing the center-of-mass
to undergo a slow random walk. This can be mitigated by resetting
the momentum at infrequent intervals using the
@ -517,7 +526,7 @@ of the underlying non-Hamiltonian equations of motion.
up to machine precision under NVT dynamics. Under NPT dynamics,
for a system with zero initial total linear momentum, the total
momentum fluctuates close to zero. It may occasionally undergo brief
excursions to non-negligible values, before returning close to zero.
excursions to non-negligible values, before returning close to zero.
Over long simulations, this has the effect of causing the center-of-mass
to undergo a slow random walk. This can be mitigated by resetting
the momentum at infrequent intervals using the
@ -685,7 +694,7 @@ Default
The keyword defaults are tchain = 3, pchain = 3, mtk = yes, tloop =
ploop = 1, nreset = 0, drag = 0.0, dilate = all, couple = none,
scaleyz = scalexz = scalexy = yes if periodic in 2nd dimension and
scaleyz = scalexz = scalexy = yes if periodic in 2nd dimension and
not coupled to barostat, otherwise no.
@ -717,6 +726,13 @@ Martyna, J Phys A: Math Gen, 39, 5629 (2006).
**(Shinoda)** Shinoda, Shiga, and Mikami, Phys Rev B, 69, 134103 (2004).
.. _nh-Dullweber:
**(Dullweber)** Dullweber, Leimkuhler and McLachlan, J Chem Phys, 107,
5840 (1997).
.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html