Unverified Commit 03985454 authored by Axel Kohlmeyer's avatar Axel Kohlmeyer
Browse files

some more formatting and math conversion improvements

parent d242051c
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+3 −3
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@@ -38,7 +38,7 @@ If an error occurs, carefully go through the steps on the
library and the :doc:`Python\_install <Python_install>` doc page about
insuring Python can find the necessary two files it needs.

**Test LAMMPS and Python in serial:**
Test LAMMPS and Python in serial:
-------------------------------------

To run a LAMMPS test in serial, type these lines into Python
@@ -67,7 +67,7 @@ typed something like:

   lmp_g++ -in in.lj

**Test LAMMPS and Python in parallel:**
Test LAMMPS and Python in parallel:
---------------------------------------

To run LAMMPS in parallel, assuming you have installed the
@@ -128,7 +128,7 @@ described in the PyPar documentation. The last line of your Python
script should be pypar.finalize(), to insure MPI is shut down
correctly.

**Running Python scripts:**
Running Python scripts:
---------------------------

Note that any Python script (not just for LAMMPS) can be invoked in
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@@ -155,17 +155,15 @@ simulation domain.

To accomplish this, if :math:`B_{ij} < B_{target}`, the :math:`C_{ij}`
prefactor for bond *ij* is incremented on the current timestep by an
amount proportional to the inverse of the specified *alpha* and the
difference (:math:`B_{ij} - B_{target}`).
Conversely if :math:`B_{ij} > B_{target}`, :math:`C_{ij}` is decremented
by the same amount.
This procedure is termed "boostostatting" in :ref:`(Voter2013) <Voter2013lhd>`.
It drives all of the individual :math:`C_{ij}` to
values such that when :math:`V^{max}_{ij}` is applied as a bias to
bond *ij*, the resulting boost factor :math:`B_{ij}` will be close
to :math:`B_{target}` on average.
Thus the LHD time acceleration factor for the overall system is
effectively *Btarget*\ .
amount proportional to the inverse of the specified :math:`\alpha` and
the difference (:math:`B_{ij} - B_{target}`).  Conversely if
:math:`B_{ij} > B_{target}`, :math:`C_{ij}` is decremented by the same
amount.  This procedure is termed "boostostatting" in :ref:`(Voter2013)
<Voter2013lhd>`.  It drives all of the individual :math:`C_{ij}` to
values such that when :math:`V^{max}_{ij}` is applied as a bias to bond
*ij*, the resulting boost factor :math:`B_{ij}` will be close to
:math:`B_{target}` on average.  Thus the LHD time acceleration factor
for the overall system is effectively *Btarget*\ .

Note that in LHD, the boost factor :math:`B_{target}` is specified by the user.
This is in contrast to global hyperdynamics (GHD) where the boost
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@@ -125,9 +125,9 @@ functions,
Full details of the lattice-Boltzmann algorithm used can be found in
:ref:`Mackay et al. <fluid-Mackay>`.

The fluid is coupled to the MD particles described by *group-ID*
through a velocity dependent force.  The contribution to the fluid
force on a given lattice mesh site j due to MD particle alpha is
The fluid is coupled to the MD particles described by *group-ID* through
a velocity dependent force.  The contribution to the fluid force on a
given lattice mesh site j due to MD particle :math:`\alpha` is
calculated as:

.. math::
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@@ -45,12 +45,12 @@ Examples
   fix 1 all qbmsst z 0.122 q 25 mu 0.9 tscale 0.01 damp 200 seed 35082 f_max 0.3 N_f 100 eta 1 beta 400 T_init 110 (liquid methane modeled with the REAX force field, real units)
   fix 2 all qbmsst z 72 q 40 tscale 0.05 damp 1 seed 47508 f_max 120.0 N_f 100 eta 1.0 beta 500 T_init 300 (quartz modeled with the BKS force field, metal units)

Two example input scripts are given, including shocked alpha quartz
and shocked liquid methane. The input script first equilibrate an
initial state with the quantum thermal bath at the target temperature
and then apply the qbmsst to simulate shock compression with quantum
nuclear correction.  The following two figures plot related quantities
for shocked alpha quartz.
Two example input scripts are given, including shocked
:math:`\alpha-\mathrm{quartz}` and shocked liquid methane.
The input script first equilibrate an initial state with the quantum
thermal bath at the target temperature and then apply the qbmsst to
simulate shock compression with quantum nuclear correction.  The
following two figures plot related quantities for shocked alpha quartz.

.. image:: JPG/qbmsst_init.jpg
   :align: center
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@@ -158,7 +158,7 @@ For style *wall/morse*\ , the energy E is given by a Morse potential:


In all cases, *r* is the distance from the particle to the wall at
position *coord*\ , and Rc is the *cutoff* distance at which the
position *coord*\ , and :math:`r_c` is the *cutoff* distance at which the
particle and wall no longer interact.  The energy of the wall
potential is shifted so that the wall-particle interaction energy is
0.0 at the cutoff distance.
@@ -185,10 +185,10 @@ box parameters and timestep and elapsed time. Thus it is easy to
specify a time-dependent wall position.  See examples below.

For the *wall/lj93* and *wall/lj126* and *wall/lj1043* styles,
*epsilon* and *sigma* are the usual Lennard-Jones parameters, which
:math:`\epsilon` and :math:`\sigma` are the usual Lennard-Jones parameters, which
determine the strength and size of the particle as it interacts with
the wall.  Epsilon has energy units.  Note that this *epsilon* and
*sigma* may be different than any *epsilon* or *sigma* values defined
the wall.  Epsilon has energy units.  Note that this :math:`\epsilon` and
:math:`\sigma` may be different than any :math:`\epsilon` or :math:`\sigma` values defined
for a pair style that computes particle-particle interactions.

The *wall/lj93* interaction is derived by integrating over a 3d
@@ -197,39 +197,39 @@ interaction is effectively a harder, more repulsive wall interaction.
The *wall/lj1043* interaction is yet a different form of wall
interaction, described in Magda et al in :ref:`(Magda) <Magda>`.

For the *wall/colloid* style, *R* is the radius of the colloid
particle, *D* is the distance from the surface of the colloid particle
to the wall (r-R), and *sigma* is the size of a constituent LJ
particle inside the colloid particle and wall.  Note that the cutoff
distance Rc in this case is the distance from the colloid particle
center to the wall.  The prefactor *epsilon* can be thought of as an
effective Hamaker constant with energy units for the strength of the
colloid-wall interaction.  More specifically, the *epsilon* pre-factor
= 4 \* pi\^2 \* rho\_wall \* rho\_colloid \* epsilon \* sigma\^6, where epsilon
and sigma are the LJ parameters for the constituent LJ
particles. Rho\_wall and rho\_colloid are the number density of the
constituent particles, in the wall and colloid respectively, in units
of 1/volume.
For the *wall/colloid* style, *R* is the radius of the colloid particle,
*D* is the distance from the surface of the colloid particle to the wall
(r-R), and :math:`\sigma` is the size of a constituent LJ particle
inside the colloid particle and wall.  Note that the cutoff distance Rc
in this case is the distance from the colloid particle center to the
wall.  The prefactor :math:`\epsilon` can be thought of as an effective
Hamaker constant with energy units for the strength of the colloid-wall
interaction.  More specifically, the :math:`\epsilon` pre-factor is
:math:`4\pi^2 \rho_{wall} \rho_{colloid} \epsilon \sigma^6`, where
:math:`\epsilon` and :math:`\sigma` are the LJ parameters for the
constituent LJ particles. :math:`\rho_{wall}` and :math:`\rho_{colloid}`
are the number density of the constituent particles, in the wall and
colloid respectively, in units of 1/volume.

The *wall/colloid* interaction is derived by integrating over
constituent LJ particles of size *sigma* within the colloid particle
and a 3d half-lattice of Lennard-Jones 12/6 particles of size *sigma*
constituent LJ particles of size :math:`\sigma` within the colloid particle
and a 3d half-lattice of Lennard-Jones 12/6 particles of size :math:`\sigma`
in the wall.  As mentioned in the preceding paragraph, the density of
particles in the wall and colloid can be different, as specified by
the *epsilon* pre-factor.
the :math:`\epsilon` pre-factor.

For the *wall/harmonic* style, *epsilon* is effectively the spring
For the *wall/harmonic* style, :math:`\epsilon` is effectively the spring
constant K, and has units (energy/distance\^2).  The input parameter
*sigma* is ignored.  The minimum energy position of the harmonic
:math:`\sigma` is ignored.  The minimum energy position of the harmonic
spring is at the *cutoff*\ .  This is a repulsive-only spring since the
interaction is truncated at the *cutoff*

For the *wall/morse* style, the three parameters are in this order:
*D\_0* the depth of the potential, *alpha* the width parameter, and
*r\_0* the location of the minimum.  *D\_0* has energy units, *alpha*
inverse distance units, and *r\_0* distance units.
:math:`D_0` the depth of the potential, :math:`\alpha` the width parameter, and
:math:`r_0` the location of the minimum.  :math:`D_0` has energy units, :math:`\alpha`
inverse distance units, and :math:`r_0` distance units.

For any wall, the *epsilon* and/or *sigma* and/or *alpha* parameter can
For any wall, the :math:`\epsilon` and/or :math:`\sigma` and/or :math:`\alpha` parameter can
be specified
as an :doc:`equal-style variable <variable>`, in which case it should be
specified as v\_name, where name is the variable name.  As with a
@@ -253,7 +253,7 @@ time. Thus it is easy to specify a time-dependent wall interaction.
   the finite-size particles of radius R must be a distance larger than R
   from the wall position *coord*\ .  The *harmonic* style is a softer
   potential and does not blow up as r -> 0, but you must use a large
   enough *epsilon* that particles always reamin on the correct side of
   enough :math:`\epsilon` that particles always reamin on the correct side of
   the wall (r > 0).

The *units* keyword determines the meaning of the distance units used
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