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@15299 f3b2605a-c512-4ea7-a41b-209d697bcdaa

Browse Source
This commit is contained in:
sjplimp
2016-07-13 21:34:23 +00:00
parent 92e5aae7bb
commit 020484f254
7 changed files with 128 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
doc/html/_sources/fix_wall_gran.txt
View File

@ -8,10 +8,15 @@ Syntax
.. parsed-literal::
fix ID group-ID wall/gran Kn Kt gamma_n gamma_t xmu dampflag wallstyle args keyword values ...
fix ID group-ID wall/gran Kn Kt fstyle gamma_n gamma_t xmu dampflag wallstyle args keyword values ...
* ID, group-ID are documented in :doc:`fix <fix>` command
* wall/gran = style name of this fix command
* fstyle = style of force interactions between particles and wall
.. parsed-literal::
possible choices: hooke, hooke/history, hertz/history
* Kn = elastic constant for normal particle repulsion (force/distance units or pressure units - see discussion below)
* Kt = elastic constant for tangential contact (force/distance units or pressure units - see discussion below)
* gamma_n = damping coefficient for collisions in normal direction (1/time units or 1/time-distance units - see discussion below)
@ -46,9 +51,9 @@ Examples
.. parsed-literal::
fix 1 all wall/gran 200000.0 NULL 50.0 NULL 0.5 0 xplane -10.0 10.0
fix 1 all wall/gran 200000.0 NULL 50.0 NULL 0.5 0 zplane 0.0 NULL
fix 2 all wall/gran 100000.0 20000.0 50.0 30.0 0.5 1 zcylinder 15.0 wiggle z 3.0 2.0
fix 1 all wall/gran hooke 200000.0 NULL 50.0 NULL 0.5 0 xplane -10.0 10.0
fix 1 all wall/gran hooke/history 200000.0 NULL 50.0 NULL 0.5 0 zplane 0.0 NULL
fix 2 all wall/gran hooke 100000.0 20000.0 50.0 30.0 0.5 1 zcylinder 15.0 wiggle z 3.0 2.0
Description
"""""""""""
@ -57,28 +62,28 @@ Bound the simulation domain of a granular system with a frictional
wall. All particles in the group interact with the wall when they are
close enough to touch it.
The first set of parameters (Kn, Kt, gamma_n, gamma_t, xmu, and
dampflag) have the same meaning as those specified with the
:doc:`pair_style granular <pair_gran>` force fields. This means a NULL
can be used for either Kt or gamma_t as described on that page. If a
NULL is used for Kt, then a default value is used where Kt = 2/7 Kn.
If a NULL is used for gamma_t, then a default value is used where
gamma_t = 1/2 gamma_n.
The nature of the wall/particle interactions are determined by the
*fstyle* setting. It can be any of the styles defined by the
:doc:`pair_style granular <pair_gran>` commands. Currently this is
*hooke*\ , *hooke/history*\ , or *hertz/history*\ . The equation for the
force between the wall and particles touching it is the same as the
corresponding equation on the :doc:`pair_style granular <pair_gran>` doc
page, in the limit of one of the two particles going to infinite
radius and mass (flat wall). I.e. delta = radius - r = overlap of
particle with wall, m_eff = mass of particle, and sqrt(RiRj/Ri+Rj)
becomes sqrt(radius of particle). The units for Kn, Kt, gamma_n, and
gamma_t are as described on that doc page. The meaning of xmu and
dampflag are also as described on that page. Note that you can choose
a different force styles and/or different values for the 6
wall/particle coefficients than for particle/particle interactions.
E.g. if you wish to model the wall as a different material.
The nature of the wall/particle interactions are determined by which
pair_style is used in your input script: *hooke*\ , *hooke/history*\ , or
*hertz/history*\ . The equation for the force between the wall and
particles touching it is the same as the corresponding equation on the
:doc:`pair_style granular <pair_gran>` doc page, in the limit of one of
the two particles going to infinite radius and mass (flat wall).
I.e. delta = radius - r = overlap of particle with wall, m_eff = mass
of particle, and sqrt(RiRj/Ri+Rj) becomes sqrt(radius of particle).
The units for Kn, Kt, gamma_n, and gamma_t are as described on that
doc page. The meaning of xmu and dampflag are also as described on
that page. Note that you can choose different values for these 6
wall/particle coefficients than for particle/particle interactions, if
you wish your wall to interact differently with the particles, e.g. if
the wall is a different material.
The parameters *Kn*\ , *Kt*\ , *gamma_n*\ , *gamma_t*\ , *xmu* and *dampflag*
have the same meaning as those specified with the :doc:`pair_style granular <pair_gran>` commands. This means a NULL can be used for
either *Kt* or *gamma_t* as described on that page. If a NULL is used
for *Kt*\ , then a default value is used where *Kt* = 2/7 *Kn*\ . If a
NULL is used for *gamma_t*\ , then a default value is used where
*gamma_t* = 1/2 *gamma_n*\ .
.. note::
@ -95,6 +100,12 @@ the wall is a different material.
Kt, gamma_n, and gamma_s should be set sqrt(2.0) larger than they were
previously.
The effective mass *m_eff* in the formulas listed on the :doc:`pair_style granular <pair_gran>` doc page is the mass of the particle for
particle/wall interactions (mass of wall is infinite). If the
particle is part of a rigid body, its mass is replaced by the mass of
the rigid body in those formulas. This is determined by searching for
a :doc:`fix rigid <fix_rigid>` command (or its variants).
The *wallstyle* can be planar or cylindrical. The 3 planar options
specify a pair of walls in a dimension. Wall positions are given by
*lo* and *hi*\ . Either of the values can be specified as NULL if a

8
doc/html/_sources/pair_gran.txt
View File

@ -91,7 +91,7 @@ The other quantities in the equations are as follows:
* gamma_n = viscoelastic damping constant for normal contact
* gamma_t = viscoelastic damping constant for tangential contact
* m_eff = Mi Mj / (Mi + Mj) = effective mass of 2 particles of mass Mi and Mj
* Delta St = tangential displacement vector between 2 spherical particles which is truncated to satisfy a frictional yield criterion
* Delta St = tangential displacement vector between 2 particles which is truncated to satisfy a frictional yield criterion
* n_ij = unit vector along the line connecting the centers of the 2 particles
* Vn = normal component of the relative velocity of the 2 particles
* Vt = tangential component of the relative velocity of the 2 particles
@ -170,6 +170,12 @@ holds, though the spring is no longer linear.
for modeling of systems which can sustain very large tangential
forces.
The effective mass *m_eff* is given by the formula above for two
isolated particles. If either particle is part of a rigid body, its
mass is replaced by the mass of the rigid body in the formula above.
This is determined by searching for a :doc:`fix rigid <fix_rigid>`
command (or its variants).
For granular styles there are no additional coefficients to set for
each pair of atom types via the :doc:`pair_coeff <pair_coeff>` command.
All settings are global and are made via the pair_style command.

61
doc/html/fix_wall_gran.html
View File

@ -128,12 +128,18 @@
<span id="index-0"></span><h1>fix wall/gran command</h1>
<div class="section" id="syntax">
<h2>Syntax</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="n">Kn</span> <span class="n">Kt</span> <span class="n">gamma_n</span> <span class="n">gamma_t</span> <span class="n">xmu</span> <span class="n">dampflag</span> <span class="n">wallstyle</span> <span class="n">args</span> <span class="n">keyword</span> <span class="n">values</span> <span class="o">...</span>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="n">Kn</span> <span class="n">Kt</span> <span class="n">fstyle</span> <span class="n">gamma_n</span> <span class="n">gamma_t</span> <span class="n">xmu</span> <span class="n">dampflag</span> <span class="n">wallstyle</span> <span class="n">args</span> <span class="n">keyword</span> <span class="n">values</span> <span class="o">...</span>
</pre></div>
</div>
<ul class="simple">
<li>ID, group-ID are documented in <a class="reference internal" href="fix.html"><span class="doc">fix</span></a> command</li>
<li>wall/gran = style name of this fix command</li>
<li>fstyle = style of force interactions between particles and wall</li>
</ul>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">possible</span> <span class="n">choices</span><span class="p">:</span> <span class="n">hooke</span><span class="p">,</span> <span class="n">hooke</span><span class="o">/</span><span class="n">history</span><span class="p">,</span> <span class="n">hertz</span><span class="o">/</span><span class="n">history</span>
</pre></div>
</div>
<ul class="simple">
<li>Kn = elastic constant for normal particle repulsion (force/distance units or pressure units - see discussion below)</li>
<li>Kt = elastic constant for tangential contact (force/distance units or pressure units - see discussion below)</li>
<li>gamma_n = damping coefficient for collisions in normal direction (1/time units or 1/time-distance units - see discussion below)</li>
@ -165,9 +171,9 @@
</div>
<div class="section" id="examples">
<h2>Examples</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="mf">200000.0</span> <span class="n">NULL</span> <span class="mf">50.0</span> <span class="n">NULL</span> <span class="mf">0.5</span> <span class="mi">0</span> <span class="n">xplane</span> <span class="o">-</span><span class="mf">10.0</span> <span class="mf">10.0</span>
<span class="n">fix</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="mf">200000.0</span> <span class="n">NULL</span> <span class="mf">50.0</span> <span class="n">NULL</span> <span class="mf">0.5</span> <span class="mi">0</span> <span class="n">zplane</span> <span class="mf">0.0</span> <span class="n">NULL</span>
<span class="n">fix</span> <span class="mi">2</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="mf">100000.0</span> <span class="mf">20000.0</span> <span class="mf">50.0</span> <span class="mf">30.0</span> <span class="mf">0.5</span> <span class="mi">1</span> <span class="n">zcylinder</span> <span class="mf">15.0</span> <span class="n">wiggle</span> <span class="n">z</span> <span class="mf">3.0</span> <span class="mf">2.0</span>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="n">hooke</span> <span class="mf">200000.0</span> <span class="n">NULL</span> <span class="mf">50.0</span> <span class="n">NULL</span> <span class="mf">0.5</span> <span class="mi">0</span> <span class="n">xplane</span> <span class="o">-</span><span class="mf">10.0</span> <span class="mf">10.0</span>
<span class="n">fix</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="n">hooke</span><span class="o">/</span><span class="n">history</span> <span class="mf">200000.0</span> <span class="n">NULL</span> <span class="mf">50.0</span> <span class="n">NULL</span> <span class="mf">0.5</span> <span class="mi">0</span> <span class="n">zplane</span> <span class="mf">0.0</span> <span class="n">NULL</span>
<span class="n">fix</span> <span class="mi">2</span> <span class="nb">all</span> <span class="n">wall</span><span class="o">/</span><span class="n">gran</span> <span class="n">hooke</span> <span class="mf">100000.0</span> <span class="mf">20000.0</span> <span class="mf">50.0</span> <span class="mf">30.0</span> <span class="mf">0.5</span> <span class="mi">1</span> <span class="n">zcylinder</span> <span class="mf">15.0</span> <span class="n">wiggle</span> <span class="n">z</span> <span class="mf">3.0</span> <span class="mf">2.0</span>
</pre></div>
</div>
</div>
@ -176,27 +182,27 @@
<p>Bound the simulation domain of a granular system with a frictional
wall. All particles in the group interact with the wall when they are
close enough to touch it.</p>
<p>The first set of parameters (Kn, Kt, gamma_n, gamma_t, xmu, and
dampflag) have the same meaning as those specified with the
<a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> force fields. This means a NULL
can be used for either Kt or gamma_t as described on that page. If a
NULL is used for Kt, then a default value is used where Kt = 2/7 Kn.
If a NULL is used for gamma_t, then a default value is used where
gamma_t = 1/2 gamma_n.</p>
<p>The nature of the wall/particle interactions are determined by which
pair_style is used in your input script: <em>hooke</em>, <em>hooke/history</em>, or
<em>hertz/history</em>. The equation for the force between the wall and
particles touching it is the same as the corresponding equation on the
<a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> doc page, in the limit of one of
the two particles going to infinite radius and mass (flat wall).
I.e. delta = radius - r = overlap of particle with wall, m_eff = mass
of particle, and sqrt(RiRj/Ri+Rj) becomes sqrt(radius of particle).
The units for Kn, Kt, gamma_n, and gamma_t are as described on that
doc page. The meaning of xmu and dampflag are also as described on
that page. Note that you can choose different values for these 6
wall/particle coefficients than for particle/particle interactions, if
you wish your wall to interact differently with the particles, e.g. if
the wall is a different material.</p>
<p>The nature of the wall/particle interactions are determined by the
<em>fstyle</em> setting. It can be any of the styles defined by the
<a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> commands. Currently this is
<em>hooke</em>, <em>hooke/history</em>, or <em>hertz/history</em>. The equation for the
force between the wall and particles touching it is the same as the
corresponding equation on the <a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> doc
page, in the limit of one of the two particles going to infinite
radius and mass (flat wall). I.e. delta = radius - r = overlap of
particle with wall, m_eff = mass of particle, and sqrt(RiRj/Ri+Rj)
becomes sqrt(radius of particle). The units for Kn, Kt, gamma_n, and
gamma_t are as described on that doc page. The meaning of xmu and
dampflag are also as described on that page. Note that you can choose
a different force styles and/or different values for the 6
wall/particle coefficients than for particle/particle interactions.
E.g. if you wish to model the wall as a different material.</p>
<p>The parameters <em>Kn</em>, <em>Kt</em>, <em>gamma_n</em>, <em>gamma_t</em>, <em>xmu</em> and <em>dampflag</em>
have the same meaning as those specified with the <a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> commands. This means a NULL can be used for
either <em>Kt</em> or <em>gamma_t</em> as described on that page. If a NULL is used
for <em>Kt</em>, then a default value is used where <em>Kt</em> = 2/7 <em>Kn</em>. If a
NULL is used for <em>gamma_t</em>, then a default value is used where
<em>gamma_t</em> = 1/2 <em>gamma_n</em>.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">As discussed on the doc page for <a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a>, versions of LAMMPS before 9Jan09 used a
@ -212,6 +218,11 @@ common case of a monodisperse system with particles of diameter 1, Kn,
Kt, gamma_n, and gamma_s should be set sqrt(2.0) larger than they were
previously.</p>
</div>
<p>The effective mass <em>m_eff</em> in the formulas listed on the <a class="reference internal" href="pair_gran.html"><span class="doc">pair_style granular</span></a> doc page is the mass of the particle for
particle/wall interactions (mass of wall is infinite). If the
particle is part of a rigid body, its mass is replaced by the mass of
the rigid body in those formulas. This is determined by searching for
a <a class="reference internal" href="fix_rigid.html"><span class="doc">fix rigid</span></a> command (or its variants).</p>
<p>The <em>wallstyle</em> can be planar or cylindrical. The 3 planar options
specify a pair of walls in a dimension. Wall positions are given by
<em>lo</em> and <em>hi</em>. Either of the values can be specified as NULL if a

7
doc/html/pair_gran.html
View File

@ -205,7 +205,7 @@ if <em>dampflag</em> is set to 0.</p>
<li>gamma_n = viscoelastic damping constant for normal contact</li>
<li>gamma_t = viscoelastic damping constant for tangential contact</li>
<li>m_eff = Mi Mj / (Mi + Mj) = effective mass of 2 particles of mass Mi and Mj</li>
<li>Delta St = tangential displacement vector between 2 spherical particles which is truncated to satisfy a frictional yield criterion</li>
<li>Delta St = tangential displacement vector between 2 particles which is truncated to satisfy a frictional yield criterion</li>
<li>n_ij = unit vector along the line connecting the centers of the 2 particles</li>
<li>Vn = normal component of the relative velocity of the 2 particles</li>
<li>Vt = tangential component of the relative velocity of the 2 particles</li>
@ -277,6 +277,11 @@ holds, though the spring is no longer linear.</p>
for modeling of systems which can sustain very large tangential
forces.</p>
</div>
<p>The effective mass <em>m_eff</em> is given by the formula above for two
isolated particles. If either particle is part of a rigid body, its
mass is replaced by the mass of the rigid body in the formula above.
This is determined by searching for a <a class="reference internal" href="fix_rigid.html"><span class="doc">fix rigid</span></a>
command (or its variants).</p>
<p>For granular styles there are no additional coefficients to set for
each pair of atom types via the <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> command.
All settings are global and are made via the pair_style command.

2
doc/html/searchindex.js
View File

File diff suppressed because one or more lines are too long

60
doc/src/fix_wall_gran.txt
View File

@ -10,10 +10,12 @@ fix wall/gran command :h3
[Syntax:]
fix ID group-ID wall/gran Kn Kt gamma_n gamma_t xmu dampflag wallstyle args keyword values ... :pre
fix ID group-ID wall/gran Kn Kt fstyle gamma_n gamma_t xmu dampflag wallstyle args keyword values ... :pre
ID, group-ID are documented in "fix"_fix.html command :ulb,l
wall/gran = style name of this fix command :l
fstyle = style of force interactions between particles and wall :l
possible choices: hooke, hooke/history, hertz/history :pre
Kn = elastic constant for normal particle repulsion (force/distance units or pressure units - see discussion below) :l
Kt = elastic constant for tangential contact (force/distance units or pressure units - see discussion below) :l
gamma_n = damping coefficient for collisions in normal direction (1/time units or 1/time-distance units - see discussion below) :l
@ -39,9 +41,9 @@ keyword = {wiggle} or {shear} :l
[Examples:]
fix 1 all wall/gran 200000.0 NULL 50.0 NULL 0.5 0 xplane -10.0 10.0
fix 1 all wall/gran 200000.0 NULL 50.0 NULL 0.5 0 zplane 0.0 NULL
fix 2 all wall/gran 100000.0 20000.0 50.0 30.0 0.5 1 zcylinder 15.0 wiggle z 3.0 2.0 :pre
fix 1 all wall/gran hooke 200000.0 NULL 50.0 NULL 0.5 0 xplane -10.0 10.0
fix 1 all wall/gran hooke/history 200000.0 NULL 50.0 NULL 0.5 0 zplane 0.0 NULL
fix 2 all wall/gran hooke 100000.0 20000.0 50.0 30.0 0.5 1 zcylinder 15.0 wiggle z 3.0 2.0 :pre
[Description:]
@ -49,28 +51,29 @@ Bound the simulation domain of a granular system with a frictional
wall. All particles in the group interact with the wall when they are
close enough to touch it.
The first set of parameters (Kn, Kt, gamma_n, gamma_t, xmu, and
dampflag) have the same meaning as those specified with the
"pair_style granular"_pair_gran.html force fields. This means a NULL
can be used for either Kt or gamma_t as described on that page. If a
NULL is used for Kt, then a default value is used where Kt = 2/7 Kn.
If a NULL is used for gamma_t, then a default value is used where
gamma_t = 1/2 gamma_n.
The nature of the wall/particle interactions are determined by the
{fstyle} setting. It can be any of the styles defined by the
"pair_style granular"_pair_gran.html commands. Currently this is
{hooke}, {hooke/history}, or {hertz/history}. The equation for the
force between the wall and particles touching it is the same as the
corresponding equation on the "pair_style granular"_pair_gran.html doc
page, in the limit of one of the two particles going to infinite
radius and mass (flat wall). I.e. delta = radius - r = overlap of
particle with wall, m_eff = mass of particle, and sqrt(RiRj/Ri+Rj)
becomes sqrt(radius of particle). The units for Kn, Kt, gamma_n, and
gamma_t are as described on that doc page. The meaning of xmu and
dampflag are also as described on that page. Note that you can choose
a different force styles and/or different values for the 6
wall/particle coefficients than for particle/particle interactions.
E.g. if you wish to model the wall as a different material.
The nature of the wall/particle interactions are determined by which
pair_style is used in your input script: {hooke}, {hooke/history}, or
{hertz/history}. The equation for the force between the wall and
particles touching it is the same as the corresponding equation on the
"pair_style granular"_pair_gran.html doc page, in the limit of one of
the two particles going to infinite radius and mass (flat wall).
I.e. delta = radius - r = overlap of particle with wall, m_eff = mass
of particle, and sqrt(RiRj/Ri+Rj) becomes sqrt(radius of particle).
The units for Kn, Kt, gamma_n, and gamma_t are as described on that
doc page. The meaning of xmu and dampflag are also as described on
that page. Note that you can choose different values for these 6
wall/particle coefficients than for particle/particle interactions, if
you wish your wall to interact differently with the particles, e.g. if
the wall is a different material.
The parameters {Kn}, {Kt}, {gamma_n}, {gamma_t}, {xmu} and {dampflag}
have the same meaning as those specified with the "pair_style
granular"_pair_gran.html commands. This means a NULL can be used for
either {Kt} or {gamma_t} as described on that page. If a NULL is used
for {Kt}, then a default value is used where {Kt} = 2/7 {Kn}. If a
NULL is used for {gamma_t}, then a default value is used where
{gamma_t} = 1/2 {gamma_n}.
NOTE: As discussed on the doc page for "pair_style
granular"_pair_gran.html, versions of LAMMPS before 9Jan09 used a
@ -86,6 +89,13 @@ common case of a monodisperse system with particles of diameter 1, Kn,
Kt, gamma_n, and gamma_s should be set sqrt(2.0) larger than they were
previously.
The effective mass {m_eff} in the formulas listed on the "pair_style
granular"_pair_gran.html doc page is the mass of the particle for
particle/wall interactions (mass of wall is infinite). If the
particle is part of a rigid body, its mass is replaced by the mass of
the rigid body in those formulas. This is determined by searching for
a "fix rigid"_fix_rigid.html command (or its variants).
The {wallstyle} can be planar or cylindrical. The 3 planar options
specify a pair of walls in a dimension. Wall positions are given by
{lo} and {hi}. Either of the values can be specified as NULL if a

8
doc/src/pair_gran.txt
View File

@ -76,7 +76,7 @@ Kt = elastic constant for tangential contact
gamma_n = viscoelastic damping constant for normal contact
gamma_t = viscoelastic damping constant for tangential contact
m_eff = Mi Mj / (Mi + Mj) = effective mass of 2 particles of mass Mi and Mj
Delta St = tangential displacement vector between 2 spherical particles \
Delta St = tangential displacement vector between 2 particles \
which is truncated to satisfy a frictional yield criterion
n_ij = unit vector along the line connecting the centers of the 2 particles
Vn = normal component of the relative velocity of the 2 particles
@ -152,6 +152,12 @@ NOTE: Normally, xmu should be specified as a fractional value between
for modeling of systems which can sustain very large tangential
forces.
The effective mass {m_eff} is given by the formula above for two
isolated particles. If either particle is part of a rigid body, its
mass is replaced by the mass of the rigid body in the formula above.
This is determined by searching for a "fix rigid"_fix_rigid.html
command (or its variants).
For granular styles there are no additional coefficients to set for
each pair of atom types via the "pair_coeff"_pair_coeff.html command.
All settings are global and are made via the pair_style command.