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<TITLE>How to get one T coupling for a multi component systems ?</TITLE>
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<P><FONT SIZE=2 FACE="Arial">Dear All:</FONT>
<BR><FONT SIZE=2 FACE="Arial">I want to run a MD of a structure composed of thousands of atoms belonging to n (n>> 2) different types.</FONT>
<BR><FONT SIZE=2 FACE="Arial">There is no bonding between atoms of the system.</FONT>
<BR><FONT SIZE=2 FACE="Arial">I developed the following .top file, which required n different T couplings</FONT>
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<P><FONT SIZE=2 FACE="Arial">%%%%%%%%%%%%%%%%%%%</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">SiG 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 SiG 1 SiG SiG 1 4.0 128.08000</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">B 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Be 1 B B 1 3.0 10.81</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">O 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 O 1 O O 1 -2.0 16.00</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Na 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Na 1 Na Na 1 1.0 22.99</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Mg 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Mg 1 Mg Mg 1 2.0 24.31</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Al 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Al 1 Al Al 1 3.0 26.98</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">As 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 As 1 As As 1 3.0 74.91</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Sr 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Sr 1 Sr Sr 1 2.0 87.62</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Ba 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; nr type resnr residue atom cgnr charge mass</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 Ba 1 Ba Ba 1 2.0 137.33</FONT>
<BR><FONT SIZE=2 FACE="Courier New">...</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ system ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">GLASS_SYSTEM</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ molecules ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">SiG </FONT>
<BR><FONT SIZE=2 FACE="Courier New">O </FONT>
<BR><FONT SIZE=2 FACE="Courier New">B</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Mg</FONT>
<BR><FONT SIZE=2 FACE="Courier New">Ba</FONT>
<BR><FONT SIZE=2 FACE="Courier New">...</FONT>
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<P><FONT SIZE=2 FACE="Arial">%%%%%%%%%%%%%%%%%%%</FONT>
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<P><FONT SIZE=2 FACE="Arial">A first guess, probably wrong, would be to consider the whole system as one molecule and gothe folowing way:</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ moleculetype ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">; name nrexcl</FONT>
<BR><FONT SIZE=2 FACE="Courier New">GLASS 0</FONT>
<BR><FONT SIZE=2 FACE="Courier New">[ atoms ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">1 SiG 1 GLASS SiG 1 4.0 28.08000</FONT>
<BR><FONT SIZE=2 FACE="Courier New">2 B 1 GLASS B 1 3.0 10.81</FONT>
<BR><FONT SIZE=2 FACE="Courier New">3 O 1 GLASS O 1 -2.0 16.00</FONT>
<BR><FONT SIZE=2 FACE="Courier New">4 Na 1 GLASS Na 1 1.0 22.99</FONT>
<BR><FONT SIZE=2 FACE="Courier New">5 Mg 1 GLASS Mg 1 2.0 24.31</FONT>
<BR><FONT SIZE=2 FACE="Courier New">6 Al 1 GLASS Al 1 3.0 26.98</FONT>
<BR><FONT SIZE=2 FACE="Courier New">7 Ca 1 GLASS Ca 1 2.0 40.08</FONT>
<BR><FONT SIZE=2 FACE="Courier New">8 As 1 GLASS As 1 3.0 74.91</FONT>
<BR><FONT SIZE=2 FACE="Courier New">9 Sr 1 GLASS Sr 1 2.0 87.62</FONT>
<BR><FONT SIZE=2 FACE="Courier New">10 Ba 1 GLASS Ba 1 2.0 137.33</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ system ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">GLASS_SYSTEM</FONT>
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<P><FONT SIZE=2 FACE="Courier New">[ molecules ]</FONT>
<BR><FONT SIZE=2 FACE="Courier New">GLASS 2004</FONT>
<BR><FONT SIZE=2 FACE="Arial"> I'm afraid that this will consider the system as composed of 2004 molecules, with a total number of atoms of 10*2004=20040!</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Any help?</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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