#include "dims.h"
      SUBROUTINE RRK(T,RMS,PS1,PS2,TP,ANS,j)
      use cons_module,only: len1,len2,kmax,rmassinv,expz,boltz,p0
C     ****
C     ****      EVALUATES  ANS = K (DIFFUSION COEFFICIENT)
C     ****
      use input_module,only: colfac
      implicit none
#include "params.h"
!
! Args:
      real,intent(in) :: T(ZIMXP,ZKMXP),RMS(ZIMXP,ZKMXP),
     |  PS1(ZIMXP,ZKMXP),PS2(ZIMXP,ZKMXP),TP(ZIMXP,ZKMXP)
      real,intent(out) :: ANS(ZIMXP,ZKMXP)
      integer,intent(in) :: j
!
! Local:
      integer :: i,k
      real :: fmin,fmax
C     ****
C     ****      SET UP expz ARRAY
C     ****
      DO 1 K=1,KMAX
        DO 2 I=1,LEN1
          ANS(I,K) = expz(K)
    2   CONTINUE
    1 CONTINUE
      DO 3 I=1,LEN2
        ANS(I,1) = 1.42E17*boltz*T(I,1)/(p0*ANS(I,1)*.5*(RMS(I,1)+
     |    RMS(I,2))*(PS2(I,1)*rmassinv(2)*SQRT(TP(I,1))*(1.-0.064*
     |    ALOG10(TP(I,1)))**2*colfac+18.6*(1.-PS1(I,1)-PS2(I,1))*
     |    rmassinv(3)+18.1*PS1(I,1)*rmassinv(1)))
    3 CONTINUE

      RETURN
      END
C