C FTRC      SOURCE    CHAT      05/01/13    00:11:11     5004           
      FUNCTION FTRC(Z,A,B,C,D)
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8 (A-H,O-Z)
      C12=SQRT(C)
      C32=C12**3
      B2=B**2
      Z2=Z**2
      TRINOM=A+B*Z+C*Z2
      TRINOM=SQRT(TRINOM)
      AC=A*C
      TERM1=B2-4.*AC
      TERM2=(2.*B2-4.*AC)*Z
      TERM3=2.*A*B
      TERM4=2.*C*D*(B*Z+2.*A)
      FTRC=(TERM2+TERM3+TERM4)/(C*TERM1*TRINOM)
      FTRC=LOG(TRINOM+Z*C12+B/(2.*C12))/C32-FTRC
      RETURN
      END