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<div class="section" id="compute-ke-atom-eff-command">
<span id="index-0"></span><h1>compute ke/atom/eff command</h1>
<div class="section" id="syntax">
<h2>Syntax</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">ke</span><span class="o">/</span><span class="n">atom</span><span class="o">/</span><span class="n">eff</span>
</pre></div>
</div>
<ul class="simple">
<li>ID, group-ID are documented in <a class="reference internal" href="compute.html"><span class="doc">compute</span></a> command</li>
<li>ke/atom/eff = style name of this compute command</li>
</ul>
</div>
<div class="section" id="examples">
<h2>Examples</h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="mi">1</span> <span class="nb">all</span> <span class="n">ke</span><span class="o">/</span><span class="n">atom</span><span class="o">/</span><span class="n">eff</span>
</pre></div>
</div>
</div>
<div class="section" id="description">
<h2>Description</h2>
<p>Define a computation that calculates the per-atom translational
(nuclei and electrons) and radial kinetic energy (electron only) in a
group. The particles are assumed to be nuclei and electrons modeled
with the <a class="reference internal" href="pair_eff.html"><span class="doc">electronic force field</span></a>.</p>
<p>The kinetic energy for each nucleus is computed as 1/2 m v^2, where m
corresponds to the corresponding nuclear mass, and the kinetic energy
for each electron is computed as 1/2 (me v^2 + 3/4 me s^2), where me
and v correspond to the mass and translational velocity of each
electron, and s to its radial velocity, respectively.</p>
<p>There is a subtle difference between the quantity calculated by this
compute and the kinetic energy calculated by the <em>ke</em> or <em>etotal</em>
keyword used in thermodynamic output, as specified by the
<a class="reference internal" href="thermo_style.html"><span class="doc">thermo_style</span></a> command. For this compute, kinetic
energy is &#8220;translational&#8221; plus electronic &#8220;radial&#8221; kinetic energy,
calculated by the simple formula above. For thermodynamic output, the
<em>ke</em> keyword infers kinetic energy from the temperature of the system
with 1/2 Kb T of energy for each (nuclear-only) degree of freedom in
eFF.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The temperature in eFF should be monitored via the <a class="reference internal" href="compute_temp_eff.html"><span class="doc">compute temp/eff</span></a> command, which can be printed with
thermodynamic output by using the <a class="reference internal" href="thermo_modify.html"><span class="doc">thermo_modify</span></a>
command, as shown in the following example:</p>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">compute</span> <span class="n">effTemp</span> <span class="nb">all</span> <span class="n">temp</span><span class="o">/</span><span class="n">eff</span>
<span class="n">thermo_style</span> <span class="n">custom</span> <span class="n">step</span> <span class="n">etotal</span> <span class="n">pe</span> <span class="n">ke</span> <span class="n">temp</span> <span class="n">press</span>
<span class="n">thermo_modify</span> <span class="n">temp</span> <span class="n">effTemp</span>
</pre></div>
</div>
<p>The value of the kinetic energy will be 0.0 for atoms (nuclei or
electrons) not in the specified compute group.</p>
<p><strong>Output info:</strong></p>
<p>This compute calculates a scalar quantity for each atom, which can be
accessed by any command that uses per-atom computes as input. See
<a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">Section_howto 15</span></a> for an overview of
LAMMPS output options.</p>
<p>The per-atom vector values will be in energy <a class="reference internal" href="units.html"><span class="doc">units</span></a>.</p>
</div>
<div class="section" id="restrictions">
<h2>Restrictions</h2>
<p>This compute is part of the USER-EFF package. It is only enabled if
LAMMPS was built with that package. See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a> section for more info.</p>
</div>
<div class="section" id="related-commands">
<h2>Related commands</h2>
<p><a class="reference internal" href="dump.html"><span class="doc">dump custom</span></a></p>
<p><strong>Default:</strong> none</p>
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