subroutine nden(val,eval)

      implicit none

      integer i,n
      parameter(n=34)
      double precision temp(n), norm(n)
      double precision val,eval,slop,y_int

      data temp/ 0.2, 0.3, 0.4, 0.5, 0.6,
     &           0.7, 0.8, 0.9, 1.0, 1.1,
     &           1.2, 1.3, 1.4, 1.5, 1.6,
     &           1.7, 1.8, 1.9, 2.0, 2.1,
     &           2.2, 2.3, 2.4, 2.5, 2.6,
     &           2.8, 3.0, 3.2, 3.4, 3.6,
     &           3.8, 4.0, 4.2, 4.4/  ! (K)
      data norm/ 0.9931507, 0.9931507, 0.9931507, 0.9931507,
     &     0.9931507, 0.9931507, 0.9931507, 0.9931507, 0.9931507,
     &     0.9931507, 0.9931507, 0.9931507, 0.9931507, 0.9938356,
     &     0.9938356, 0.9945205, 0.9952055, 0.9958904, 0.9972603,
     &     0.9986301, 1.0000000, 0.9979452, 0.9952055, 0.9917809,
     &     0.9876713, 0.9787672, 0.9671233, 0.9534247, 0.9376712,
     &     0.9198630, 0.9006850, 0.8794520, 0.8568493, 0.8328767/
*
      do i=1,n-1
         if(val.lt.temp(1).or.val.gt.temp(n)) then
            write(*,*) val,temp(1),temp(n)
            write(*,*) 'The value is out of range ... nden code'
            stop
         elseif(val.eq.temp(i)) then
            eval = norm(i)
         elseif(val.eq.temp(i+1)) then
            eval = norm(i+1)
         elseif(val.gt.temp(i).and.val.lt.temp(i+1)) then
            slop = (norm(i+1)-norm(i))/(temp(i+1)-temp(i))
            y_int = norm(i) - slop*temp(i)
            eval = slop*val+y_int
         else
            continue
         endif
      enddo

      return
      end