36.12 Forming an outer product of two vectors (OPRD)

OPRD,result,matrix,orb1,orb2,factor

Takes the column vectors v1 and v2 from matrix and adds their outer product to result. v1 and v2 must be given in the form icol.isym, e.g., 3.2 means the third vector in symmetry 2. The result is

$result(a,b)=result(a,b) + factor*v1(a)*v2(b)$

If result has not been used before, it is zeroed before performing the operation.