anchor.diff: -C$Id: ecp_3j_prod.f,v 1.2 1996-10-11 16:47:45 d3e129 Exp $
  +C$Id: ecp_3j_prod.f,v 1.3 1997-05-14 17:57:09 mg201 Exp $
   ************************************************************************
   *                                                                      *
         subroutine ecp_3j_prod (l1,l2,l3,m1,m2,result)
  
positive.code:         m_mid = m3
        end if
        phase = (abs(m1)+abs(m2)+abs(m3))/2
  C      phase = 0
        if (m_min .lt. 0) then
          m_min = -m_min
          m_mid = -m_mid
          m_max = -m_max
        end if
  C      write (6,*) 'reordered arguments'
  C      write (6,'(3I4)') l_min,l_mid,l_max
  C      write (6,'(3I4)') m_min,m_mid,m_max
  *
  *   Special code for l_min = 0
  *
  
negative.code: *   Calculate product of 3j symbols which appears in the angular       * 
  *   integral over three spherical tensors. Product is                  *
  *   (l1 l2 l3 / m1 m2 m3) (l1 l2 l3 / 0 0 0).                          *
  *                                                                      *
  *   l1,l2,l3 - l values                                                *
  *   m1,m2 - m values; m3 = -(m1+m2)                                    *
  