      t0 = 2.D0/3.D0*M/(R+2*M)**2*sqrt(6.D0)*sqrt(pi)
                                dRB1m1(1)=t0

      t0 = cmplx(0.D0,2.D0/3.D0)*M/(R+2*M)**2*sqrt(6.D0)*sqrt(pi)
                                dRB1m1(2)=t0

      t0 = 0
                                dRB1m1(3)=t0

