code: def Dlmk(l,m,k,phi1,phi2,theta1,theta2):
      
      
      return exp(complex(0.,-m*phi1)) * dlmk(l,m,k,theta1) * \
        exp(complex(0.,-k*gamma(phi1,phi2,theta1,theta2)))
docs: returns value of D^l_mk as defined in allen, ottewill 97.