only count if 2nd atom is the one storing the angle

   all atoms in interaction must be in group

   all atoms in interaction must be known to proc

   if angle is deleted (type = 0), do not count

   if angle is turned off (type < 0), still count

------------------------------------------------------------------------- */

int ComputePropertyLocal::count_angles(int flag)

      if (atom1 < 0 || !(mask[atom1] & groupbit)) continue;

      atom3 = atom->map(angle_atom3[atom2][i]);

      if (atom3 < 0 || !(mask[atom3] & groupbit)) continue;

      if (angle_type[atom2][i] == 0) continue;

      if (flag) {

	indices[m][0] = atom2;