C KTETMC    SOURCE    CHAT      05/01/13    01:10:41     5004           

             FUNCTION KTETMC (T)
      IMPLICIT INTEGER(I-N)
      real*8 t,aa,bb,ktetMC
      real*8            coh,phi,ar,tmax,aap,aan,bbp,bbn
      common /rhmcdata/ coh,phi,ar,tmax,aap,aan,bbp,bbn
      if (abs(t).gt.tmax) then
        aa = aap
        bb = bbp
        if (t.lt.0.D0) then
         aa = aan
         bb = bbn
        endif
        ktetMC = aa-bb*sin(3.D0*t)
      else
        ktetMC = cos(t)-sin(phi)*sin(t)/sqrt(3.D0)
      endif
      return
      end