    (4) A_4 (energy units)
               (5) A_5 (energy units)
          class2
               currently not enabled for &quot;dihedral coeff&quot; command
               must be specified in data file (see &quot;read data&quot; command)
          charmm
               (1) K (energy units)
               (2) n (1,2,3,4,6)
               (3) d (0 or 180 degrees) (converted to radians within LAMMPS)
               (4) weighting factor to turn on/off 1-4 neighbor nonbond interactions

define (or override) di