* * Topology File for Mie General model (Mick, Soroush Barhaghi, and Potoff) United Atom Force Field * * Parameters From: * * "Mie potentials for phase equilibria calculations: Application to alkanes and perfluoroalkanes." * Potoff, Jeffrey J., and Damien A. Bernard-Brunel. * The Journal of Physical Chemistry B 113.44 (2009): 14725-14731. * * * "Optimized Mie Potentials for Phase Equilibria: Understanding the limits of transferability in branched alkanes" * Jason R. Mick, Mohammad Soroush Barhaghi, Jeffrey J. Potoff. * * BONDS ! !V(bond) = Kb(b - b0)**2 ! !Kb: kcal/mole/A**2 !b0: A ! ! Kb (kcal/mol) = Kb (K) * Boltz. const.; (9999999999 if no stretching) ! !atom type Kb b0 description CH3 CH3 9999999999 1.540 ! (ex. ethane) CH3 CH2 9999999999 1.540 ! (ex. propane) CH2 CH2 9999999999 1.540 ! (ex. n-butane) CH3 CH1 9999999999 1.540 ! (ex. 2-methylpropane) CH3 CT 9999999999 1.540 ! (ex. 2-methylpentane) CH2 CH1 9999999999 1.540 ! (ex. 2,2-dimethylpropane) CH2 CT 9999999999 1.540 ! (ex. 2,2-dimethylbutane) CH1 CH1 9999999999 1.540 ! (ex. 2,3-dimethylbutane) CH1 CT 9999999999 1.540 ! (ex. 2,2,3-trimethylbutane) CTT CTT 9999999999 1.580 ! (ex. 2,2,3,3-tetramethylbutane) ANGLES ! !V(angle) = Ktheta(Theta - Theta0)**2 ! !Ktheta: kcal/mole/rad**2 !Theta0: degrees ! ! Ktheta (kcal/mol) = Ktheta (K) * Boltz. const. ! !atom types Ktheta Theta0 CH3 CH2 CH3 31250 114.00 ! (propane only) CH3 CH2 CH2 31250 114.00 ! (ex. n-butane) CH3 CH2 CH1 31250 114.00 ! (ex. 2-methylbutane) CH3 CH2 CT 31250 114.00 ! (ex. 2,2-dimethylbutane) CH2 CH2 CH2 31250 114.00 ! (ex. n-pentane) CH2 CH2 CH1 31250 114.00 ! (ex. 2-methylpentane) CH2 CH2 CT 31250 114.00 ! (ex. 2,2-dimethylpentane) CH1 CH2 CH1 31250 114.00 ! (ex. 2,4-dimethylpentane) CH1 CH2 CT 31250 114.00 ! (ex. 2,2,4-trimethylpentane) CH3 CH1 CH3 31250 112.00 ! (ex. 2-methylpropane) CH3 CH1 CH2 31250 112.00 ! (ex. 2-methylpentane) CH3 CH1 CH1 31250 112.00 ! (ex. 2-methylbutane) CH3 CH1 CT 31250 112.00 ! (ex. 2-methylpentane) CH2 CH1 CH2 31250 112.00 ! (ex. 2,3-dimethylbutane) CH2 CH1 CH1 31250 112.00 ! (ex. 2,3-dimethylpentane) CH2 CH1 CT 31250 112.00 ! (ex. 2,2,3-trimethylbutane) CH1 CH1 CH1 31250 112.00 ! (ex. 2,3,4-trimethylpentane) CH3 CT CH3 31250 109.47 ! (ex. 2,2-dimethylpropane) CH3 CT CH2 31250 109.47 ! (ex. 2,2-dimethylbutane) CH3 CT CH1 31250 109.47 ! (ex. 2,2,3-trimethylbutane) CH2 CT CH2 31250 109.47 ! (ex. 3,3-dimethylpentane) CH3 CTT CTT 31250 111.00 ! (2,2,3,3-tetramethylbutane) CH3 CTT CH3 31250 107.00 ! (2,2,3,3-tetramethylbutane) DIHEDRALS ! !V(dihedral) = Kchi(1 + cos(n(chi) - delta)) ! !Kchi: kcal/mole !n: multiplicity !delta: degrees ! ! Kchi (kcal/mol) = Kchi (K) * Boltz. const. ! Boltzmann = 0.0019872041 kcal / (mol * K) ! ! TraPPE Inherits most of its dihedrals from OPLS UA ! X-CT-CH1-X fitted to QM data in this work ! !atom types Kchi n delta description X CH2 CH2 X 0.000000 0 0.0 ! OPLS (ex. n-butane) X CH2 CH2 X 355.029964 1 0.0 ! "" X CH2 CH2 X -68.189775 2 180.0 ! "" X CH2 CH2 X 791.317812 3 0.0 ! "" X CH2 CH1 X -251.059767 0 0.0 ! OPLS (ex. 2-methylbutane) X CH2 CH1 X 428.729993 1 0.0 ! "" X CH2 CH1 X -111.850111 2 180.0 ! "" X CH2 CH1 X 441.270224 3 0.0 ! "" X CH1 CH1 X -251.059767 0 0.0 ! OPLS (ex. 2,3-dimethylbutane) X CH1 CH1 X 428.729993 1 0.0 ! "" X CH1 CH1 X -111.850111 2 180.0 ! "" X CH1 CH1 X 441.270224 3 0.0 ! "" X CT CH2 X 461.289809 3 0.0 ! OPLS (ex. 2,2-dimethylbutane) X CT CH1 X 1369.00000 3 0.0 ! this work (ex. 2,2,3-TriMPe) X CT CT X 2950.910000 0 0.0 ! this work -- from QM X CT CT X -2047.060000 3 0.0 ! (ex. 2,2,3,3-tetramethylbutane) X CT CT X 529.250000 6 180.0 ! "" X CT CT X 150.160000 12 0.0 ! "" NONBONDED_MIE ! !V(mie) = 4*eps*((sig_ij/r_ij)^n-(sig_ij/r_ij)^6) ! !atom eps sig_ij n description CH4 161.00 3.740 14 ! Potoff, 2009 CH3 121.25 3.783 16 ! Potoff, 2009 CH2 61.00 3.990 16 ! Potoff, 2009 CH1 15.00 4.600 16 ! (this work) CT 1.20 6.100 16 ! (this work) CTT 1.20 6.100 16 ! 2,2,3,3-tetramethylbutane (same as CT)