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<DIV><FONT face=Arial size=2>Dear All:</FONT></DIV>
<DIV><FONT face=Arial size=2> I am
using GROMACS 3.1.4 to simulating 2-walled carbon nanotubes, as:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial
size=2>
---------------------</FONT></DIV>
<DIV><FONT face=Arial
size=2>
---------------------------------------</FONT></DIV>
<DIV><FONT face=Arial
size=2>
--------------------------------------- ->
Inner Layer Tubule</FONT></DIV>
<DIV><FONT face=Arial
size=2>
---------------------
-> Outer Layer Tubule</FONT></DIV>
<DIV><FONT face=Arial size=2>
Intralayer potential I use morse bonds and G96 angles, Interlayer I use
L-J(6-12) potential,</FONT></DIV>
<DIV><FONT face=Arial size=2>and I write files as:</FONT></DIV>
<DIV><FONT face=Arial size=2>1)nt.gro:</FONT></DIV>
<DIV><FONT face=Arial size=2>multiwalled nanotube</FONT></DIV>
<DIV><FONT face=Arial size=2> 400</FONT></DIV>
<DIV><FONT face=Arial size=2> 1 NT_I
C_I 1 3.294 2.830
2.570 .0000 .0000 .0000</FONT></DIV>
<DIV><FONT face=Arial size=2> ....</FONT></DIV>
<DIV><FONT face=Arial size=2> 1 NT_I
C_I 200 3.294 2.830
2.570 .0000 .0000 .0000</FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face=Arial size=2> 1
NT_O C_O 201 3.294
2.830 2.570 .0000 .0000
.0000</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2> ....</FONT></DIV>
<DIV><FONT face=Arial size=2> 20 20 50</FONT></DIV>
<DIV><FONT face=Arial size=2>(I use C_I and C_O to specify the carbon atom in
innertube and outertube)</FONT></DIV>
<DIV><FONT face=Arial size=2>2)nt.top</FONT></DIV>
<DIV><FONT face=Arial size=2>#include "nt.itp"<BR>[ moleculetype
]<BR> nt 1<BR> [ atoms ]<BR>
1 C_I 1 MWNT C_I
1 .000 12.011<BR>......</FONT></DIV>
<DIV><FONT face=Arial size=2>(I do not need charge group, so set them from
1~400, because the large number of the same charge group must <64
?) </FONT></DIV>
<DIV><FONT face=Arial size=2>[bonds]<BR> 1
2 3 .141800
478.900000 21.867000</FONT></DIV>
<DIV><FONT face=Arial size=2>......</FONT></DIV>
<DIV><FONT face=Arial size=2>[angles]<BR> 1
2 14 2 120.000000
562.200000<BR> ...... <BR>[ system ]<BR> MultiWalled
Nanotube<BR>[ molecules ]<BR> nt 1<BR>3)nt.itp</FONT></DIV>
<DIV><FONT face=Arial size=2>[ atomtypes ]<BR>
C_I 12.01100
0.000 A 0.298007
2.1961<BR> C_O 12.01100
0.000 A 0.298007
2.1961<BR>[ nonbond_params ]<BR> C_I
C_O 1 0.298007 2.1961 <BR> C_O
C_I 1 0.298007 2.1961 </FONT></DIV>
<DIV><FONT face=Arial size=2>[ bondtypes ]<BR>C_I
C_I 3 0.1418 478.9 21.867<BR>C_O
C_O 3 0.1418 478.9 21.867<BR>[ angletypes
]<BR>C_I C_I C_I
2 120 562.2
<BR>C_O C_O C_O
2 120 562.2</FONT></DIV>
<DIV><FONT face=Arial size=2>4)em.mdp</FONT></DIV>
<DIV><FONT face=Arial
size=2>title
= nt<BR>constraints
= none<BR>integrator
=
steep<BR>dt
= 0.002 ; ps
!<BR>nsteps
=
100<BR>nstlist
=
10<BR>ns_type
=
grid<BR>rlist
=
1.0<BR>rvdw
=
1.0<BR>emtol
=
100.0<BR>emstep
= 0.01</FONT></DIV>
<DIV><FONT face=Arial size=2>--------------------------------------</FONT></DIV>
<DIV><FONT face=Arial size=2>That's all, but I do not know why it will not
converge, and if I run md, if will give bad results.</FONT></DIV>
<DIV><FONT size=2><FONT face=Arial>I am a freshuser of gromacs, If this post
abrupt you, I will be very sorry.</FONT></FONT></DIV>
<DIV><FONT size=2><FONT face=Arial>thank you.</FONT></FONT></DIV>
<DIV><FONT size=2><FONT face=Arial><BR> </DIV></FONT></FONT>
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