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<div align="center"> <font size="5"> <b><font face="Arial, Helvetica, sans-serif"><a name="top"></a>MCCCS
Towhee (SMMK Main)</font></b> </font> </div>
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<td width="697" valign="top"> <b>Overview</b>
<ul>
This section covers the Siepmann-Martin-Mundy-Klein (SMMK) force field for branched alkanes as it is implemented
into the towhee_ff_SMMKmain file in the ForceFields directory. All of the Towhee atom types for this force field
are listed, along with a short description of their meanings.
SMMKmain uses a 'Lennard-Jones' classical_potential and the 'Geometric' classical_mixrule.
Unlike its predecessor (<a href="sks.html">SKS</a>) the SMMKmain force field uses tail corrections,
and was originally used with a 13.8 Angstrom cutoff.
The SMMKmain forcefield is an extension of the <a href="sks.html">SKS</a> force field for linear alkanes and
was immediately supplanted by similar parameters included in the same paper
(see <a href="smmknaip.html">SMMK Note Added in Proof</a> and eventually replaced by the
<a href="trappeua.html">TraPPE-UA</a> force field.
Any discrepencies (especially typos) from the published force field values are the sole
responsibility of Marcus G. Martin, and I welcome feedback on how this
implementation compares with other programs.
</ul>
<b>References for SMMK Main</b>
<ul>
Most of the nonbonded parameters and detailed results for the SMMK Main force field are found in the main text of the
following paper.
<ul>
<li><a href="../references.html#siepmann_et_al_1997">Siepmann <i>et al.</i> 1997</a></li>
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This is a fully flexible model where the intramolecular terms for all of the atoms, and some special One-Five
nonbonded terms for <b>CH3methyl</b> groups are taken from.
<ul>
<li><a href="../references.html#mundy_et_al_1996">Mundy <i>et al.</i> 1996</a></li>
</ul>
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<b>SMMK Main in Towhee</b>
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The official force field name for SMMK Main in Towhee is 'SMMKmain'. Here
I list all of the atom names for use in the towhee_input file, along with a brief description.
Please note that the capitalization and spacing pattern is important and must be followed exactly
as listed here.
<ul>
<li><b>'CH3long'</b> methyl group (C plus 3 bonded H as a united-atom) on an <i>n</i>-alkane of C<sub>4</sub> or longer,
or on an alkyl side-chain of length propyl or longer.</li>
<li><b>'CH3ethyl'</b> methyl group (C plus 3 bonded H as a united-atom) on an ethyl side-chain.</li>
<li><b>'CH3methyl'</b> methyl group (C plus 3 bonded H as a united-atom) on an methyl side-chain.</li>
<li><b>'CH2'</b> methylene group (C plus 2 bonded H as a united-atom).</li>
<li><b>'CH'</b> methine group (C plus 1 bonded H as a united-atom).</li>
<li><b>'C'</b> quaternary carbon.</li>
</ul>
</ul>
<b>Coulombic interactions</b>
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There are no coulombic interactions for this force field.
</ul>
<a href="../towhee_capabilities.html">Return to the Towhee Capabilities web page</a>
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<i><font size="2">Send comments to:</font></i> <font size="2">
<a href="mailto:marcus_martin@users.sourceforge.net">Marcus G. Martin</a><br>
<i>Last updated:</i>
<!-- #BeginDate format:Am1 -->November 10, 2005<!-- #EndDate -->
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