FUNCTION GFREE(T,FR)
C     ====================
C
C     Hydrogenic free-free Gaunt factor, for temperature T and
C     frequency FR
C
      INCLUDE 'PARAMS.FOR'
      THET=5040.4/T
      IF(THET.LT.4.E-2) THET=4.E-2
      X=FR/2.99793E14
      IF(X.GT.1) GO TO 10
      IF(X.LT.0.2) X=0.2
      GFREE=(1.0823+2.98E-2/THET)+(6.7E-3+1.12E-2/THET)/X
      RETURN
   10 C1=(3.9999187E-3-7.8622889E-5/THET)/THET+1.070192
      C2=(6.4628601E-2-6.1953813E-4/THET)/THET+2.6061249E-1
      C3=(1.3983474E-5/THET+3.7542343E-2)/THET+5.7917786E-1
      C4=3.4169006E-1+1.1852264E-2/THET
      GFREE=((C4/X-C3)/X+C2)/X+C1
      RETURN
      END