<spanid="index-0"></span><h1>fix shardlow command<aclass="headerlink"href="#fix-shardlow-command"title="Permalink to this headline">¶</a></h1>
<divclass="section"id="syntax">
<h2>Syntax<aclass="headerlink"href="#syntax"title="Permalink to this headline">¶</a></h2>
<divclass="highlight-python"><divclass="highlight"><pre>fix ID group-ID shardlow
</pre></div>
</div>
<ulclass="simple">
<li>ID, group-ID are documented in <aclass="reference internal"href="fix.html"><em>fix</em></a> command</li>
<li>shardlow = style name of this fix command</li>
</ul>
</div>
<divclass="section"id="examples">
<h2>Examples<aclass="headerlink"href="#examples"title="Permalink to this headline">¶</a></h2>
<divclass="highlight-python"><divclass="highlight"><pre>fix 1 all shardlow
</pre></div>
</div>
</div>
<divclass="section"id="description">
<h2>Description<aclass="headerlink"href="#description"title="Permalink to this headline">¶</a></h2>
<p>Specifies that the Shardlow splitting algorithm (SSA) is to be used to
integrate the DPD equations of motion. The SSA splits the integration
into a stochastic and deterministic integration step. The fix
<em>shardlow</em> performs the stochastic integration step and must be used
in conjunction with a deterministic integrator (e.g. <aclass="reference internal"href="fix_nve.html"><em>fix nve</em></a> or <codeclass="xref doc docutils literal"><spanclass="pre">fix</span><spanclass="pre">nph</span></code>). The stochastic
integration of the dissipative and random forces is performed prior to
the deterministic integration of the conservative force. Further
details regarding the method are provided in <aclass="reference internal"href="pair_dpd_fdt.html#lisal"><span>(Lisal)</span></a> and
<p>The fix <em>shardlow</em> must be used with the <aclass="reference internal"href="pair_style.html"><em>pair_style dpd/fdt</em></a> or <aclass="reference internal"href="pair_style.html"><em>pair_style dpd/fdt/energy</em></a> command to properly initialize the
fluctuation-dissipation theorem parameter(s) sigma (and kappa, if
necessary).</p>
<p>Note that numerous variants of DPD can be specified by choosing an
appropriate combination of the integrator and <aclass="reference internal"href="pair_style.html"><em>pair_style dpd/fdt</em></a> command. DPD under isothermal conditions can
be specified by using fix <em>shardlow</em>, fix <em>nve</em> and pair_style
<em>dpd/fdt</em>. DPD under isoenergetic conditions can be specified by
using fix <em>shardlow</em>, fix <em>nve</em> and pair_style <em>dpd/fdt/energy</em>. DPD
under isobaric conditions can be specified by using fix shardlow, fix
<em>nph</em> and pair_style <em>dpd/fdt</em>. DPD under isoenthalpic conditions can
be specified by using fix shardlow, fix <em>nph</em> and pair_style
<em>dpd/fdt/energy</em>. Examples of each DPD variant are provided in the
examples/USER/dpd directory.</p>
</div>
<hrclass="docutils"/>
<divclass="section"id="restrictions">
<h2>Restrictions<aclass="headerlink"href="#restrictions"title="Permalink to this headline">¶</a></h2>
<p>This fix is only available if LAMMPS is built with the USER-DPD
package. See the <aclass="reference internal"href="Section_start.html#start-3"><span>Making LAMMPS</span></a> section
for more info.</p>
<p>This fix is currently limited to orthogonal simulation cell
geometries.</p>
<p>This fix must be used with an additional fix that specifies time
integration, e.g. <aclass="reference internal"href="fix_nve.html"><em>fix nve</em></a> or <aclass="reference internal"href="fix_nh.html"><em>fix nph</em></a>.</p>
<p>The Shardlow splitting algorithm requires the sizes of the sub-domain
lengths to be larger than twice the cutoff+skin. Generally, the
domain decomposition is dependant on the number of processors
requested.</p>
</div>
<divclass="section"id="related-commands">
<h2>Related commands<aclass="headerlink"href="#related-commands"title="Permalink to this headline">¶</a></h2>
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