FUNCTION SGHE12(FR)
C     ===================
C
C     Special formula for the photoionization cross-section from the
C     averaged <n=2> level of He I
C
      INCLUDE 'IMPLIC.FOR'
      PARAMETER (C1=3.D0,C2=9.D0,C3=1.6D1,T15=1.D-15,
     * A1=6.45105D-18,A2=3.02D-19,A3=9.9847D-18,A4=1.1763673D-17,
     * A5=3.63662D-19,A6=-2.783D2,A7=1.488D1,A8=-2.311D-1,
     * E1=3.5D0,E2=3.6D0,E3=1.91D0,E4=2.9D0,E5=3.3D0)
C
      X=FR*T15
      XX=LOG(FR)
      SGHE12=(C1*(A1/X**E1+A2/X**E2)+A3/X**E3+C2*(A4/X**E4+A5/X**E5)+
     *       C1*EXP(A6+XX*(A7+XX*A8)))/C3
      RETURN
      END