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 'PARAMS.FOR'
      DATA C1/3.E0/,C2/9.E0/,C3/1.6E1/,
     * A1/6.45105E-18/,A2/3.02E-19/,A3/9.9847E-18/,A4/1.1763673E-17/,
     * A5/3.63662E-19/,A6/-2.783E2/,A7/1.488E1/,A8/-2.311E-1/,
     * E1/3.5E0/,E2/3.6E0/,E3/1.91E0/,E4/2.9E0/,E5/3.3E0/
      X=FR*1.E-15
      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