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612 lines
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<li>pair_style eam command</li>
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<div class="section" id="pair-style-eam-command">
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<span id="index-0"></span><h1>pair_style eam command</h1>
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</div>
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<div class="section" id="pair-style-eam-gpu-command">
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<h1>pair_style eam/gpu command</h1>
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</div>
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<div class="section" id="pair-style-eam-kk-command">
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<h1>pair_style eam/kk command</h1>
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</div>
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<div class="section" id="pair-style-eam-omp-command">
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<h1>pair_style eam/omp command</h1>
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</div>
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<div class="section" id="pair-style-eam-opt-command">
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<h1>pair_style eam/opt command</h1>
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</div>
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<div class="section" id="pair-style-eam-alloy-command">
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<h1>pair_style eam/alloy command</h1>
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</div>
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<div class="section" id="pair-style-eam-alloy-gpu-command">
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<h1>pair_style eam/alloy/gpu command</h1>
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</div>
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<div class="section" id="pair-style-eam-alloy-kk-command">
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<h1>pair_style eam/alloy/kk command</h1>
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</div>
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<div class="section" id="pair-style-eam-alloy-omp-command">
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<h1>pair_style eam/alloy/omp command</h1>
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</div>
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<div class="section" id="pair-style-eam-alloy-opt-command">
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<h1>pair_style eam/alloy/opt command</h1>
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</div>
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<div class="section" id="pair-style-eam-cd-command">
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<h1>pair_style eam/cd command</h1>
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</div>
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<div class="section" id="pair-style-eam-cd-omp-command">
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<h1>pair_style eam/cd/omp command</h1>
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</div>
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<div class="section" id="pair-style-eam-fs-command">
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<h1>pair_style eam/fs command</h1>
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</div>
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<div class="section" id="pair-style-eam-fs-gpu-command">
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<h1>pair_style eam/fs/gpu command</h1>
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</div>
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<div class="section" id="pair-style-eam-fs-kk-command">
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<h1>pair_style eam/fs/kk command</h1>
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</div>
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<div class="section" id="pair-style-eam-fs-omp-command">
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<h1>pair_style eam/fs/omp command</h1>
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</div>
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<div class="section" id="pair-style-eam-fs-opt-command">
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<h1>pair_style eam/fs/opt command</h1>
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<div class="section" id="syntax">
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<h2>Syntax</h2>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_style</span> <span class="n">style</span>
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</pre></div>
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</div>
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<ul class="simple">
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<li>style = <em>eam</em> or <em>eam/alloy</em> or <em>eam/cd</em> or <em>eam/fs</em></li>
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</ul>
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</div>
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<div class="section" id="examples">
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<h2>Examples</h2>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_style</span> <span class="n">eam</span>
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<span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="n">cuu3</span>
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<span class="n">pair_coeff</span> <span class="mi">1</span><span class="o">*</span><span class="mi">3</span> <span class="mi">1</span><span class="o">*</span><span class="mi">3</span> <span class="n">niu3</span><span class="o">.</span><span class="n">eam</span>
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</pre></div>
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</div>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_style</span> <span class="n">eam</span><span class="o">/</span><span class="n">alloy</span>
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<span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="o">../</span><span class="n">potentials</span><span class="o">/</span><span class="n">NiAlH_jea</span><span class="o">.</span><span class="n">eam</span><span class="o">.</span><span class="n">alloy</span> <span class="n">Ni</span> <span class="n">Al</span> <span class="n">Ni</span> <span class="n">Ni</span>
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</pre></div>
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</div>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_style</span> <span class="n">eam</span><span class="o">/</span><span class="n">cd</span>
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<span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="o">../</span><span class="n">potentials</span><span class="o">/</span><span class="n">FeCr</span><span class="o">.</span><span class="n">cdeam</span> <span class="n">Fe</span> <span class="n">Cr</span>
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</pre></div>
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</div>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_style</span> <span class="n">eam</span><span class="o">/</span><span class="n">fs</span>
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<span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="n">NiAlH_jea</span><span class="o">.</span><span class="n">eam</span><span class="o">.</span><span class="n">fs</span> <span class="n">Ni</span> <span class="n">Al</span> <span class="n">Ni</span> <span class="n">Ni</span>
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</pre></div>
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</div>
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</div>
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<div class="section" id="description">
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<h2>Description</h2>
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<p>Style <em>eam</em> computes pairwise interactions for metals and metal alloys
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using embedded-atom method (EAM) potentials <a class="reference internal" href="pair_polymorphic.html#daw"><span class="std std-ref">(Daw)</span></a>. The total
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energy Ei of an atom I is given by</p>
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<img alt="_images/pair_eam.jpg" class="align-center" src="_images/pair_eam.jpg" />
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<p>where F is the embedding energy which is a function of the atomic
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electron density rho, phi is a pair potential interaction, and alpha
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and beta are the element types of atoms I and J. The multi-body
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nature of the EAM potential is a result of the embedding energy term.
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Both summations in the formula are over all neighbors J of atom I
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within the cutoff distance.</p>
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<p>The cutoff distance and the tabulated values of the functionals F,
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rho, and phi are listed in one or more files which are specified by
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the <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> command. These are ASCII text files
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in a DYNAMO-style format which is described below. DYNAMO was the
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original serial EAM MD code, written by the EAM originators. Several
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DYNAMO potential files for different metals are included in the
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“potentials” directory of the LAMMPS distribution. All of these files
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are parameterized in terms of LAMMPS <a class="reference internal" href="units.html"><span class="doc">metal units</span></a>.</p>
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<div class="admonition note">
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<p class="first admonition-title">Note</p>
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<p class="last">The <em>eam</em> style reads single-element EAM potentials in the
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DYNAMO <em>funcfl</em> format. Either single element or alloy systems can be
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modeled using multiple <em>funcfl</em> files and style <em>eam</em>. For the alloy
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case LAMMPS mixes the single-element potentials to produce alloy
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potentials, the same way that DYNAMO does. Alternatively, a single
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DYNAMO <em>setfl</em> file or Finnis/Sinclair EAM file can be used by LAMMPS
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to model alloy systems by invoking the <em>eam/alloy</em> or <em>eam/cd</em> or
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<em>eam/fs</em> styles as described below. These files require no mixing
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since they specify alloy interactions explicitly.</p>
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</div>
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<div class="admonition note">
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<p class="first admonition-title">Note</p>
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<p class="last">Note that unlike for other potentials, cutoffs for EAM
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potentials are not set in the pair_style or pair_coeff command; they
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are specified in the EAM potential files themselves. Likewise, the
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EAM potential files list atomic masses; thus you do not need to use
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the <a class="reference internal" href="mass.html"><span class="doc">mass</span></a> command to specify them.</p>
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</div>
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<p>There are several WWW sites that distribute and document EAM
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potentials stored in DYNAMO or other formats:</p>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">http</span><span class="p">:</span><span class="o">//</span><span class="n">www</span><span class="o">.</span><span class="n">ctcms</span><span class="o">.</span><span class="n">nist</span><span class="o">.</span><span class="n">gov</span><span class="o">/</span><span class="n">potentials</span>
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<span class="n">http</span><span class="p">:</span><span class="o">//</span><span class="n">cst</span><span class="o">-</span><span class="n">www</span><span class="o">.</span><span class="n">nrl</span><span class="o">.</span><span class="n">navy</span><span class="o">.</span><span class="n">mil</span><span class="o">/</span><span class="n">ccm6</span><span class="o">/</span><span class="n">ap</span>
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<span class="n">http</span><span class="p">:</span><span class="o">//</span><span class="n">enpub</span><span class="o">.</span><span class="n">fulton</span><span class="o">.</span><span class="n">asu</span><span class="o">.</span><span class="n">edu</span><span class="o">/</span><span class="n">cms</span><span class="o">/</span><span class="n">potentials</span><span class="o">/</span><span class="n">main</span><span class="o">/</span><span class="n">main</span><span class="o">.</span><span class="n">htm</span>
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</pre></div>
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</div>
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<p>These potentials should be usable with LAMMPS, though the alternate
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formats would need to be converted to the DYNAMO format used by LAMMPS
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and described on this page. The NIST site is maintained by Chandler
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Becker (cbecker at nist.gov) who is good resource for info on
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interatomic potentials and file formats.</p>
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<hr class="docutils" />
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<p>For style <em>eam</em>, potential values are read from a file that is in the
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DYNAMO single-element <em>funcfl</em> format. If the DYNAMO file was created
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by a Fortran program, it cannot have “D” values in it for exponents.
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C only recognizes “e” or “E” for scientific notation.</p>
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<p>Note that unlike for other potentials, cutoffs for EAM potentials are
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not set in the pair_style or pair_coeff command; they are specified in
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the EAM potential files themselves.</p>
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<p>For style <em>eam</em> a potential file must be assigned to each I,I pair of
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atom types by using one or more pair_coeff commands, each with a
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single argument:</p>
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<ul class="simple">
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<li>filename</li>
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</ul>
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<p>Thus the following command</p>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_coeff</span> <span class="o">*</span><span class="mi">2</span> <span class="mi">1</span><span class="o">*</span><span class="mi">2</span> <span class="n">cuu3</span><span class="o">.</span><span class="n">eam</span>
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</pre></div>
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</div>
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<p>will read the cuu3 potential file and use the tabulated Cu values for
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F, phi, rho that it contains for type pairs 1,1 and 2,2 (type pairs
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1,2 and 2,1 are ignored). See the <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> doc
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page for alternate ways to specify the path for the potential file.
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In effect, this makes atom types 1 and 2 in LAMMPS be Cu atoms.
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Different single-element files can be assigned to different atom types
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to model an alloy system. The mixing to create alloy potentials for
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type pairs with I != J is done automatically the same way that the
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serial DYNAMO code originally did it; you do not need to specify
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coefficients for these type pairs.</p>
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<p><em>Funcfl</em> files in the <em>potentials</em> directory of the LAMMPS
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distribution have an ”.eam” suffix. A DYNAMO single-element <em>funcfl</em>
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file is formatted as follows:</p>
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<ul class="simple">
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<li>line 1: comment (ignored)</li>
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<li>line 2: atomic number, mass, lattice constant, lattice type (e.g. FCC)</li>
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<li>line 3: Nrho, drho, Nr, dr, cutoff</li>
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</ul>
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<p>On line 2, all values but the mass are ignored by LAMMPS. The mass is
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in mass <a class="reference internal" href="units.html"><span class="doc">units</span></a>, e.g. mass number or grams/mole for metal
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units. The cubic lattice constant is in Angstroms. On line 3, Nrho
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and Nr are the number of tabulated values in the subsequent arrays,
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drho and dr are the spacing in density and distance space for the
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values in those arrays, and the specified cutoff becomes the pairwise
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cutoff used by LAMMPS for the potential. The units of dr are
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Angstroms; I’m not sure of the units for drho - some measure of
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electron density.</p>
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<p>Following the three header lines are three arrays of tabulated values:</p>
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<ul class="simple">
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<li>embedding function F(rho) (Nrho values)</li>
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<li>effective charge function Z(r) (Nr values)</li>
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<li>density function rho(r) (Nr values)</li>
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</ul>
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<p>The values for each array can be listed as multiple values per line,
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so long as each array starts on a new line. For example, the
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individual Z(r) values are for r = 0,dr,2*dr, ... (Nr-1)*dr.</p>
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<p>The units for the embedding function F are eV. The units for the
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density function rho are the same as for drho (see above, electron
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density). The units for the effective charge Z are “atomic charge” or
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sqrt(Hartree * Bohr-radii). For two interacting atoms i,j this is used
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by LAMMPS to compute the pair potential term in the EAM energy
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expression as r*phi, in units of eV-Angstroms, via the formula</p>
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<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">r</span><span class="o">*</span><span class="n">phi</span> <span class="o">=</span> <span class="mf">27.2</span> <span class="o">*</span> <span class="mf">0.529</span> <span class="o">*</span> <span class="n">Zi</span> <span class="o">*</span> <span class="n">Zj</span>
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</pre></div>
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</div>
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<p>where 1 Hartree = 27.2 eV and 1 Bohr = 0.529 Angstroms.</p>
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<hr class="docutils" />
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<p>Style <em>eam/alloy</em> computes pairwise interactions using the same
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formula as style <em>eam</em>. However the associated
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<a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> command reads a DYNAMO <em>setfl</em> file
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instead of a <em>funcfl</em> file. <em>Setfl</em> files can be used to model a
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single-element or alloy system. In the alloy case, as explained
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above, <em>setfl</em> files contain explicit tabulated values for alloy
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interactions. Thus they allow more generality than <em>funcfl</em> files for
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modeling alloys.</p>
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<p>For style <em>eam/alloy</em>, potential values are read from a file that is
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in the DYNAMO multi-element <em>setfl</em> format, except that element names
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(Ni, Cu, etc) are added to one of the lines in the file. If the
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DYNAMO file was created by a Fortran program, it cannot have “D”
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values in it for exponents. C only recognizes “e” or “E” for
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scientific notation.</p>
|
|
<p>Only a single pair_coeff command is used with the <em>eam/alloy</em> style
|
|
which specifies a DYNAMO <em>setfl</em> file, which contains information for
|
|
M elements. These are mapped to LAMMPS atom types by specifying N
|
|
additional arguments after the filename in the pair_coeff command,
|
|
where N is the number of LAMMPS atom types:</p>
|
|
<ul class="simple">
|
|
<li>filename</li>
|
|
<li>N element names = mapping of <em>setfl</em> elements to atom types</li>
|
|
</ul>
|
|
<p>As an example, the potentials/NiAlH_jea.eam.alloy file is a <em>setfl</em>
|
|
file which has tabulated EAM values for 3 elements and their alloy
|
|
interactions: Ni, Al, and H. See the <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> doc
|
|
page for alternate ways to specify the path for the potential file.
|
|
If your LAMMPS simulation has 4 atoms types and you want the 1st 3 to
|
|
be Ni, and the 4th to be Al, you would use the following pair_coeff
|
|
command:</p>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="n">NiAlH_jea</span><span class="o">.</span><span class="n">eam</span><span class="o">.</span><span class="n">alloy</span> <span class="n">Ni</span> <span class="n">Ni</span> <span class="n">Ni</span> <span class="n">Al</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>The 1st 2 arguments must be * * so as to span all LAMMPS atom types.
|
|
The first three Ni arguments map LAMMPS atom types 1,2,3 to the Ni
|
|
element in the <em>setfl</em> file. The final Al argument maps LAMMPS atom
|
|
type 4 to the Al element in the <em>setfl</em> file. Note that there is no
|
|
requirement that your simulation use all the elements specified by the
|
|
<em>setfl</em> file.</p>
|
|
<p>If a mapping value is specified as NULL, the mapping is not performed.
|
|
This can be used when an <em>eam/alloy</em> potential is used as part of the
|
|
<em>hybrid</em> pair style. The NULL values are placeholders for atom types
|
|
that will be used with other potentials.</p>
|
|
<p><em>Setfl</em> files in the <em>potentials</em> directory of the LAMMPS distribution
|
|
have an ”.eam.alloy” suffix. A DYNAMO multi-element <em>setfl</em> file is
|
|
formatted as follows:</p>
|
|
<ul class="simple">
|
|
<li>lines 1,2,3 = comments (ignored)</li>
|
|
<li>line 4: Nelements Element1 Element2 ... ElementN</li>
|
|
<li>line 5: Nrho, drho, Nr, dr, cutoff</li>
|
|
</ul>
|
|
<p>In a DYNAMO <em>setfl</em> file, line 4 only lists Nelements = the # of
|
|
elements in the <em>setfl</em> file. For LAMMPS, the element name (Ni, Cu,
|
|
etc) of each element must be added to the line, in the order the
|
|
elements appear in the file.</p>
|
|
<p>The meaning and units of the values in line 5 is the same as for the
|
|
<em>funcfl</em> file described above. Note that the cutoff (in Angstroms) is
|
|
a global value, valid for all pairwise interactions for all element
|
|
pairings.</p>
|
|
<p>Following the 5 header lines are Nelements sections, one for each
|
|
element, each with the following format:</p>
|
|
<ul class="simple">
|
|
<li>line 1 = atomic number, mass, lattice constant, lattice type (e.g. FCC)</li>
|
|
<li>embedding function F(rho) (Nrho values)</li>
|
|
<li>density function rho(r) (Nr values)</li>
|
|
</ul>
|
|
<p>As with the <em>funcfl</em> files, only the mass (in mass <a class="reference internal" href="units.html"><span class="doc">units</span></a>,
|
|
e.g. mass number or grams/mole for metal units) is used by LAMMPS from
|
|
the 1st line. The cubic lattice constant is in Angstroms. The F and
|
|
rho arrays are unique to a single element and have the same format and
|
|
units as in a <em>funcfl</em> file.</p>
|
|
<p>Following the Nelements sections, Nr values for each pair potential
|
|
phi(r) array are listed for all i,j element pairs in the same format
|
|
as other arrays. Since these interactions are symmetric (i,j = j,i)
|
|
only phi arrays with i >= j are listed, in the following order: i,j =
|
|
(1,1), (2,1), (2,2), (3,1), (3,2), (3,3), (4,1), ..., (Nelements,
|
|
Nelements). Unlike the effective charge array Z(r) in <em>funcfl</em> files,
|
|
the tabulated values for each phi function are listed in <em>setfl</em> files
|
|
directly as r*phi (in units of eV-Angstroms), since they are for atom
|
|
pairs.</p>
|
|
<hr class="docutils" />
|
|
<p>Style <em>eam/cd</em> is similar to the <em>eam/alloy</em> style, except that it
|
|
computes alloy pairwise interactions using the concentration-dependent
|
|
embedded-atom method (CD-EAM). This model can reproduce the enthalpy
|
|
of mixing of alloys over the full composition range, as described in
|
|
<a class="reference internal" href="#stukowski"><span class="std std-ref">(Stukowski)</span></a>.</p>
|
|
<p>The pair_coeff command is specified the same as for the <em>eam/alloy</em>
|
|
style. However the DYNAMO <em>setfl</em> file must has two
|
|
lines added to it, at the end of the file:</p>
|
|
<ul class="simple">
|
|
<li>line 1: Comment line (ignored)</li>
|
|
<li>line 2: N Coefficient0 Coefficient1 ... CoeffincientN</li>
|
|
</ul>
|
|
<p>The last line begins with the degree <em>N</em> of the polynomial function
|
|
<em>h(x)</em> that modifies the cross interaction between A and B elements.
|
|
Then <em>N+1</em> coefficients for the terms of the polynomial are then
|
|
listed.</p>
|
|
<p>Modified EAM <em>setfl</em> files used with the <em>eam/cd</em> style must contain
|
|
exactly two elements, i.e. in the current implementation the <em>eam/cd</em>
|
|
style only supports binary alloys. The first and second elements in
|
|
the input EAM file are always taken as the <em>A</em> and <em>B</em> species.</p>
|
|
<p><em>CD-EAM</em> files in the <em>potentials</em> directory of the LAMMPS
|
|
distribution have a ”.cdeam” suffix.</p>
|
|
<hr class="docutils" />
|
|
<p>Style <em>eam/fs</em> computes pairwise interactions for metals and metal
|
|
alloys using a generalized form of EAM potentials due to Finnis and
|
|
Sinclair <a class="reference internal" href="#finnis"><span class="std std-ref">(Finnis)</span></a>. The total energy Ei of an atom I is
|
|
given by</p>
|
|
<img alt="_images/pair_eam_fs.jpg" class="align-center" src="_images/pair_eam_fs.jpg" />
|
|
<p>This has the same form as the EAM formula above, except that rho is
|
|
now a functional specific to the atomic types of both atoms I and J,
|
|
so that different elements can contribute differently to the total
|
|
electron density at an atomic site depending on the identity of the
|
|
element at that atomic site.</p>
|
|
<p>The associated <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a> command for style <em>eam/fs</em>
|
|
reads a DYNAMO <em>setfl</em> file that has been extended to include
|
|
additional rho_alpha_beta arrays of tabulated values. A discussion of
|
|
how FS EAM differs from conventional EAM alloy potentials is given in
|
|
<a class="reference internal" href="#ackland1"><span class="std std-ref">(Ackland1)</span></a>. An example of such a potential is the same
|
|
author’s Fe-P FS potential <a class="reference internal" href="#ackland2"><span class="std std-ref">(Ackland2)</span></a>. Note that while FS
|
|
potentials always specify the embedding energy with a square root
|
|
dependence on the total density, the implementation in LAMMPS does not
|
|
require that; the user can tabulate any functional form desired in the
|
|
FS potential files.</p>
|
|
<p>For style <em>eam/fs</em>, the form of the pair_coeff command is exactly the
|
|
same as for style <em>eam/alloy</em>, e.g.</p>
|
|
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">pair_coeff</span> <span class="o">*</span> <span class="o">*</span> <span class="n">NiAlH_jea</span><span class="o">.</span><span class="n">eam</span><span class="o">.</span><span class="n">fs</span> <span class="n">Ni</span> <span class="n">Ni</span> <span class="n">Ni</span> <span class="n">Al</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>where there are N additional arguments after the filename, where N is
|
|
the number of LAMMPS atom types. See the <a class="reference internal" href="pair_coeff.html"><span class="doc">pair_coeff</span></a>
|
|
doc page for alternate ways to specify the path for the potential
|
|
file. The N values determine the mapping of LAMMPS atom types to EAM
|
|
elements in the file, as described above for style <em>eam/alloy</em>. As
|
|
with <em>eam/alloy</em>, if a mapping value is NULL, the mapping is not
|
|
performed. This can be used when an <em>eam/fs</em> potential is used as
|
|
part of the <em>hybrid</em> pair style. The NULL values are used as
|
|
placeholders for atom types that will be used with other potentials.</p>
|
|
<p>FS EAM files include more information than the DYNAMO <em>setfl</em> format
|
|
files read by <em>eam/alloy</em>, in that i,j density functionals for all
|
|
pairs of elements are included as needed by the Finnis/Sinclair
|
|
formulation of the EAM.</p>
|
|
<p>FS EAM files in the <em>potentials</em> directory of the LAMMPS distribution
|
|
have an ”.eam.fs” suffix. They are formatted as follows:</p>
|
|
<ul class="simple">
|
|
<li>lines 1,2,3 = comments (ignored)</li>
|
|
<li>line 4: Nelements Element1 Element2 ... ElementN</li>
|
|
<li>line 5: Nrho, drho, Nr, dr, cutoff</li>
|
|
</ul>
|
|
<p>The 5-line header section is identical to an EAM <em>setfl</em> file.</p>
|
|
<p>Following the header are Nelements sections, one for each element I,
|
|
each with the following format:</p>
|
|
<ul class="simple">
|
|
<li>line 1 = atomic number, mass, lattice constant, lattice type (e.g. FCC)</li>
|
|
<li>embedding function F(rho) (Nrho values)</li>
|
|
<li>density function rho(r) for element I at element 1 (Nr values)</li>
|
|
<li>density function rho(r) for element I at element 2</li>
|
|
<li>...</li>
|
|
<li>density function rho(r) for element I at element Nelement</li>
|
|
</ul>
|
|
<p>The units of these quantities in line 1 are the same as for <em>setfl</em>
|
|
files. Note that the rho(r) arrays in Finnis/Sinclair can be
|
|
asymmetric (i,j != j,i) so there are Nelements^2 of them listed in the
|
|
file.</p>
|
|
<p>Following the Nelements sections, Nr values for each pair potential
|
|
phi(r) array are listed in the same manner (r*phi, units of
|
|
eV-Angstroms) as in EAM <em>setfl</em> files. Note that in Finnis/Sinclair,
|
|
the phi(r) arrays are still symmetric, so only phi arrays for i >= j
|
|
are listed.</p>
|
|
<hr class="docutils" />
|
|
<p>Styles with a <em>gpu</em>, <em>intel</em>, <em>kk</em>, <em>omp</em>, or <em>opt</em> suffix are
|
|
functionally the same as the corresponding style without the suffix.
|
|
They have been optimized to run faster, depending on your available
|
|
hardware, as discussed in <a class="reference internal" href="Section_accelerate.html"><span class="doc">Section_accelerate</span></a>
|
|
of the manual. The accelerated styles take the same arguments and
|
|
should produce the same results, except for round-off and precision
|
|
issues.</p>
|
|
<p>These accelerated styles are part of the GPU, USER-INTEL, KOKKOS,
|
|
USER-OMP and OPT packages, respectively. They are only enabled if
|
|
LAMMPS was built with those packages. 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>
|
|
<p>You can specify the accelerated styles explicitly in your input script
|
|
by including their suffix, or you can use the <a class="reference internal" href="Section_start.html#start-7"><span class="std std-ref">-suffix command-line switch</span></a> when you invoke LAMMPS, or you can
|
|
use the <a class="reference internal" href="suffix.html"><span class="doc">suffix</span></a> command in your input script.</p>
|
|
<p>See <a class="reference internal" href="Section_accelerate.html"><span class="doc">Section_accerlate</span></a> of the manual for more
|
|
instructions on how to use the accelerated styles effectively.</p>
|
|
<hr class="docutils" />
|
|
<p><strong>Mixing, shift, table, tail correction, restart, rRESPA info</strong>:</p>
|
|
<p>For atom type pairs I,J and I != J, where types I and J correspond to
|
|
two different element types, mixing is performed by LAMMPS as
|
|
described above with the individual styles. You never need to specify
|
|
a pair_coeff command with I != J arguments for the eam styles.</p>
|
|
<p>This pair style does not support the <a class="reference internal" href="pair_modify.html"><span class="doc">pair_modify</span></a>
|
|
shift, table, and tail options.</p>
|
|
<p>The eam pair styles do not write their information to <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>, since it is stored in tabulated potential files.
|
|
Thus, you need to re-specify the pair_style and pair_coeff commands in
|
|
an input script that reads a restart file.</p>
|
|
<p>The eam pair styles can only be used via the <em>pair</em> keyword of the
|
|
<a class="reference internal" href="run_style.html"><span class="doc">run_style respa</span></a> command. They do not support the
|
|
<em>inner</em>, <em>middle</em>, <em>outer</em> keywords.</p>
|
|
</div>
|
|
<hr class="docutils" />
|
|
<div class="section" id="restrictions">
|
|
<h2>Restrictions</h2>
|
|
<p>All of these styles except the <em>eam/cd</em> style are part of the MANYBODY
|
|
package. They are only enabled if LAMMPS was built with that package
|
|
(which it is by default). 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>
|
|
<p>The <em>eam/cd</em> style is part of the USER-MISC package and also requires
|
|
the MANYBODY package. It is only enabled if LAMMPS was built with
|
|
those packages. 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="pair_coeff.html"><span class="doc">pair_coeff</span></a></p>
|
|
<p><strong>Default:</strong> none</p>
|
|
<hr class="docutils" />
|
|
<p id="ackland1"><strong>(Ackland1)</strong> Ackland, Condensed Matter (2005).</p>
|
|
<p id="ackland2"><strong>(Ackland2)</strong> Ackland, Mendelev, Srolovitz, Han and Barashev, Journal
|
|
of Physics: Condensed Matter, 16, S2629 (2004).</p>
|
|
<p id="daw"><strong>(Daw)</strong> Daw, Baskes, Phys Rev Lett, 50, 1285 (1983).
|
|
Daw, Baskes, Phys Rev B, 29, 6443 (1984).</p>
|
|
<p id="finnis"><strong>(Finnis)</strong> Finnis, Sinclair, Philosophical Magazine A, 50, 45 (1984).</p>
|
|
<p id="stukowski"><strong>(Stukowski)</strong> Stukowski, Sadigh, Erhart, Caro; Modeling Simulation
|
|
Materials Science & Engineering, 7, 075005 (2009).</p>
|
|
</div>
|
|
</div>
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