 use straight LJ, pairs between inner and outer use a smoothed LJ,
   and the potential goes to 0.0 at the outer cutoff
for lj/smooth and lj/charmm styles, energy and forces are continuous at inner
   cutoff and go smoothly to zero at outer cutoff
for lj/shift and soft styles, must set &quot;coulomb style&quot; to &quot;none&quot;
for lj/charmm style, must set &quot;coulomb style&quot; to &quot;charmm/switch&quot;, &quot;pppm&quot;,
   or &quot;ewald&quot;
for lj/shift style, delta shift distances for each 