<html> <head> <title>MCCCS Towhee (Square Well)</title> </head> <body bgcolor="#FFFFFF" text="#000000"> <table width="675" border="0" cellspacing="0" cellpadding="0" height="590"> <tr> <td colspan="2" height="29"> <div align="center"> <font size="5"> <b><font face="Arial, Helvetica, sans-serif"><a name="top"></a>MCCCS Towhee (Square Well)</font></b> </font> </div> </td> </tr> <A href="http://sourceforge.net"> <IMG src="http://sourceforge.net/sflogo.php?group_id=87039&type=5" width="210" height="62" border="0" alt="SourceForge.net Logo" align="right"/> </A> <tr> <td width="18" height="371" valign="top"> <p> </p> <p> </p> </td> <td width="697" valign="top"> <b>Overview</b> <ul> This section covers Square Well parameters as they are implemented into the towhee_ff_SquareWell file in the ForceFields directory. It is a bit strong to call this a force field, as all there is not much to a square well potential, but this file explains how to use the builder with the square well potential, and how to add in any other square well parameters that you might want to use in a simulation. </ul> <b>Square Well in Towhee</b> <ul> The official force field name for Square Well in Towhee is 'SquareWell'. Here I list all of the Square Well atom names currently in use for the towhee_input file, along with a brief description (although the meaning of the atom names should be obvious). If you want to add any new parameters into Towhee just take a look in the <a href="../potentype/towhee_input_classical_potential.html">towhee_input classical_potential</a> documentation for a complete description of the functional form. I am happy to add some more of these parameter sets into the release version as well (only takes a few minutes). The distance units are in Angstroms, and the well depth is in Kelvin divided by Boltzmann's constant. Please note that the capitalization and spacing pattern is important and must be followed exactly as listed here. <ul> <li><b>'type_a'</b> : sigma [nbcoeff(1)] is 1.0, lamda [nbcoeff(2)] is 1.5, and the well depth [nbcoeff(3)] is 1.0.</li> <li><b>'type_b'</b> : sigma [nbcoeff(1)] is 2.0, lamda [nbcoeff(2)] is 3.0, and the well depth [nbcoeff(3)] is 1.0.</li> </ul> </ul> <b>Coulombic interactions</b> <ul> It is possible to combine the square well potential with point charges. Simply assign the point charges to the atoms as you see fit. </ul> <a href="../towhee_capabilities.html">Return to the Towhee Capabilities web page</a> <p> </p> </td> </tr> </table> <hr width="715" align="left"> <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 -->September 07, 2005<!-- #EndDate --> </font> <br> </body> </html>