[gmx-users] Topology file for fullerene c60

[Marine Bozdaganyan]

Dear users!

I'm trying to make forcefield oplsaa for fullerene. I already have modified
files (see it in the end of the letter), but i have a problem with torsion
parameters - torsion angles are different, but atom type is the same -
alkene. Length and angles were taken as an average. After pdb2gmx i have
normal .gro and .top file (but with wrong parameters for torsions). during
the minimization my system blows.

Could anyone give any clue about my problem? May be somebody already has
right topology file for my fullerene.

Thank you in advance.

_________________________

*ffoplsaa.atp*

 opls_141B 12.01100 ; fullerene

__________________________

*ffoplsaanb.itp*

; name bond_type mass charge ptype sigma epsilon

opls_141B C3 6 12.01100 0.000 A 3.47000e-01 2.76470e-01

__________________________

*ffoplsaa.rtp*

[ FUL ]
 [ atoms ]
  CF1 opls_141B 0.000 1
  CF2 opls_141B 0.000 1
  CF3 opls_141B 0.000 1
  CF4 opls_141B 0.000 1
  CF5 opls_141B 0.000 1
  CF6 opls_141B 0.000 1
  .........
  CF60 opls_141B 0.000 1
 [ bonds ]
  CF1 CF2
  CF2 CF3
  CF3 CF9
  CF5 CF6
  CF7 CF18
  CF8 CF20
  CF10 CF14
  CF11 CF24
  CF13 CF26
  CF15 CF28
  CF17 CF30

..................
  CF19 CF21
  CF21 CF31
  CF23 CF32
  CF25 CF34
  .............

____________

*ffoplsaabon.itp*

[ bondtypes ]
; i j func b0 kb
  C3 C3 1 0.14200 265265.6

[ angletypes ]
; i j k func th0 cth
  C3 C3 C3 1 114.000 488.273 ;

[ dihedraltypes ]
; i j k l func coefficients
  C3 C3 C3 C3 3 -4.96013 6.28646 1.30959 -2.63592 0.00000 0.00000 ;
fullerene
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