FUNCTION EXTPRF(DLAM,IT,ILINE,ANEL,DLAST,PLAST)
C     ===============================================
C
C     Extrapolation in wavelengths in Shamey, or Barnard, Cooper,
C     Smith tables
C     Special formula suggested by Cooper
C
      INCLUDE 'PARAMS.FOR'
      DIMENSION W0(4,4)
      DATA W0    / 1.460, 1.269, 1.079, 0.898,
     *             6.130, 5.150, 4.240, 3.450,
     *             4.040, 3.490, 2.960, 2.470,
     *             2.312, 1.963, 1.624, 1.315/
C
      WE=W0(IT,ILINE)*EXP(ANEL*2.3025851)*1.E-16
      DLASTA=ABS(DLAST)
      D52=DLASTA*DLASTA*SQRT(DLASTA)
      F=D52*(PLAST-WE/3.14159/DLAST/DLAST)
      EXTPRF=(WE/3.14159+F/SQRT(ABS(DLAM)))/DLAM/DLAM
      RETURN
      END