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mmeineke |
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! This is the forcefield file for the TraPPE force field. |
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! the sections are divided into AtomTypes, BondTypes, BendTypes, |
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! and TorsionTypes. |
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#AtomTypes |
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!Atom mass LJ epsilon ( kcal/mol) LJ sigma (Angstroms) |
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CH4 16.05 0.279 3.73 |
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CH3 15.04 0.185 3.75 |
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CH2 14.03 0.0866 3.95 |
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#BondTypes |
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!Atom1 Atom2 type distance |
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CH3 CH3 fixed 1.54 |
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CH3 CH2 fixed 1.54 |
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CH2 CH2 fixed 1.54 |
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#BendTypes |
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!Atom1 Atom2 Atom3 type k1 k2 k3 theta_0 ( k1 -> kcal/mol/degrees^2; theta_0 ->degrees ) |
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!V_bend = k1 * ( th - th0 ) + k2 * ( th - th0 ) + k3 |
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CH3 CH2 CH3 quadratic 58.84 0.0 0.0 114.0 |
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CH3 CH2 CH2 quadratic 58.84 0.0 0.0 114.0 |
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CH2 CH2 CH2 quadratic 58.84 0.0 0.0 114.0 |
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#TorsionTypes |
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!Atom1 Atom2 Atom3 Atom4 type k1 k2 k3 k4 ( all are kcal/mol ) |
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!V_torsion = k1(cos phi)^3 + k2(cos phi)^2 + k3(cos phi) + k4 |
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CH3 CH2 CH2 CH3 cubic 5.9602 -0.2568 -3.802 2.1586 |
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CH3 CH2 CH2 CH2 cubic 5.9602 -0.2568 -3.802 2.1586 |
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CH2 CH2 CH2 CH2 cubic 5.9602 -0.2568 -3.802 2.1586 |
