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<TITLE>Adding 3 body force field term into Gromacs</TITLE>
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<P><FONT SIZE=2 FACE="Arial">Dear ALL:</FONT>
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<P><FONT SIZE=2 FACE="Arial">Has anyone tried to add a tree body term in Gromacs?</FONT>
<BR><FONT SIZE=2 FACE="Arial">Any functional like Stillinger-Weber (SW) or Axilrod-Teller (AT)?</FONT>
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<P><FONT SIZE=2 FACE="Arial">SW: e*a*exp(b*<I></I></FONT><I><FONT SIZE=2 FACE="Courier New">(1/(r12/c-d)+1/(r13/c-d)))*(cos(theta)-cos(theta_0))**2</FONT></I>
<BR><I><FONT SIZE=2 FACE="Courier New">where e,a,b,c,d,theta_0 are fixed </FONT></I>
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<P><FONT SIZE=2 FACE="Courier New">AT: Z_123*[1+cos(theta_123)*cos(theta_231)*cos(theta_312)]/[r_12*r_13_r_23]^3</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Where Z_123 is fixed</FONT>
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<P><FONT SIZE=2 FACE="Courier New">Thanks a lot,</FONT>
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<P><FONT SIZE=2 FACE="Courier New">Adama</FONT>
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<P><FONT SIZE=2 FACE="Arial">Adama Tandia</FONT>
<BR><FONT SIZE=2 FACE="Arial">Modeling & Simulation</FONT>
<BR><FONT SIZE=2 FACE="Arial">Corning INC</FONT>
<BR><FONT SIZE=2 FACE="Arial">Corning, NY 14831 USA</FONT>
<BR><FONT SIZE=2 FACE="Arial">Tel: 607 248 1036</FONT>
<BR><FONT SIZE=2 FACE="Arial">Fax: 607 974 3405</FONT>
<BR><A HREF="www.corning.com"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">www.corning.com</FONT></U></A>
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