More spherical harmonics added.

o Replaced Cartesians in the reciprocal and self PME terms.
o Added non-PME spherical harmonics field generation and force evaluation routines.
o Added spherical harmonic potential evaluation, to allow removal of the Cartesian moments.

plugins/amoeba/platforms/reference/src/SimTKReference/AmoebaReferenceMultipoleForce.h

@@ -824,14 +824,14 @@ protected:
      * which is the rotation matrix that describes the orientation of the
      * internuclear vector for a given pair (I,J) in lab frame.
      *
-     * @param particleI             particleI data
-     * @param particleJ             particleJ data
+     * @param particleI             particleI position
+     * @param particleJ             particleJ position
      * @param deltaR                the internuclear vector, corrected for periodic boundary conditions
      * @param r                     the bond length between atoms I and J
      * @param rotationmatrix        the output rotation matrix for a 3-vector
      */
-    void formQIRotationMatrix(const MultipoleParticleData& particleI,
-                              const MultipoleParticleData& particleJ,
+    void formQIRotationMatrix(const RealVec& iPosition,
+                              const RealVec& jPosition,
                               const RealVec &deltaR,
                               RealOpenMM r,
                               RealOpenMM (&rotationMatrix)[3][3]) const;