[gmx-users] itp for rigid acetone

[Xin Liu]

 	the parameter of acetone in the literature( JPC 94, 1990, p.1683) are given in the following manner,
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atom types  charge sigma epsilon 
CH3          0.062  3.910 0.160
C            0.300  3.750 0.105
O          -0.424  2.960 0.210
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 C=O distance :0.1222 nm CH3-C distance: 0.1507 angles: O=C-CH3:121.44 CH3-C-CH3:117.12
In the model,  the bond lengths and bond angles have been kept fixed for all MD simulation of acetone.
I have no idea on how to set up the itp file for aceton so that the bond lengths and bond angles have been kept fixed
Somebody can help me to give me the case of itp file.			
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Xin Liu
2009-04-29