C CINVAT    SOURCE    CHAT      05/01/12    22:02:47     5004           

      SUBROUTINE C_INVARI_T (SIG,N,T)
      IMPLICIT INTEGER(I-N)
      integer n
      complex*16 sig(n),t,J2,J3
      call C_Invari_J2(sig,n,J2)
      t=0.D0
      if (abs(J2).gt.1.D-17) then
         call C_Invari_J3(sig,n,J3)
         t=3.D0*sqrt(3.D0)*J3/(2.D0*J2**1.5D0)
c         if (abs(t).lt.-1.D0) t=-1.D0
c         if (abs(t).gt.1.D0)  t= 1.D0         
         t=-(0,1.D0)*log(t+sqrt(1.D0-t*t)*(0,1.D0))/3.D0
      endif
      return
      end