1* \\\\\\\ United Atom Butane Parameters (Charmm "extened" model) /////// 2* \\\\\\\ most recent update Tues April 5th by Paul R Brenner //////// 3* \\ based on data from Barth, LeimKuhler, and Reich 2002 Charmm19 //// 4* \ dihedral energy according to Izaguirre and Hampton 2004 Charmm19 / 5 6BONDS 7! 8!V(bond) = Kb(b - b0)**2 9! 10!Kb: kcal/mole/A**2 11!b0: A 12! 13!atom type Kb b0 14! 15 16CH2 CH2 225.000 1.520 ! from CHARMM version 19 17CH2 CH3 225.000 1.540 ! from CHARMM version 19 18 19 20ANGLES 21! 22!V(angle) = Ktheta(Theta - Theta0)**2 23! 24!V(Urey-Bradley) = Kub(S - S0)**2 25! 26!Ktheta: kcal/mole/rad**2 27!Theta0: degrees 28!Kub: kcal/mole/A**2 (Urey-Bradley) 29!S0: A 30! 31!atom types Ktheta Theta0 Kub S0 32! 33 34CH3 CH2 CH2 45.00 110.00 ! United Atom Butane 35 36 37DIHEDRALS 38! 39!V(dihedral) = Kchi(1 + cos(n(chi) - delta)) 40! 41!Kchi: kcal/mole 42!n: multiplicity 43!delta: degrees 44! 45!atom types Kchi n delta 46! 47 48CH3 CH2 CH2 CH3 1.6000 3 0.00 ! United atom butane 49CH3 CH2 CH2 CH3 0.6 1 0.00 ! United Atom butane 50 51 52NONBONDED nbxmod 5 atom cdiel fshift vatom vdistance vfswitch - 53!cutnb 14.0 ctofnb 12.0 ctonnb 10.0 eps 1.0 e14fac 1.0 wmin 1.5 54! 55!V(Lennard-Jones) = Eps,i,j[(Rmin,i,j/ri,j)**12 - 2(Rmin,i,j/ri,j)**6] 56! 57!epsilon: kcal/mole, Eps,i,j = sqrt(eps,i * eps,j) 58!Rmin/2: A, Rmin,i,j = Rmin/2,i + Rmin/2,j 59! 60!atom ignored epsilon Rmin/2 ignored eps,1-4 Rmin/2,1-4 61! 62CH2 0.0 -0.1142 2.235 ! UA butane 63CH3 0.0 -0.1811 2.165 ! UA butane 64 65 66NBFIX 67! Emin Rmin 68! (kcal/mol) (A) 69! 70 71HBOND CUTHB 0.5 ! If you want to do hbond analysis (only), then use 72 ! READ PARAM APPEND CARD 73 ! to append hbond parameters from the file: par_hbond.inp 74 75END 76