      module mo_lin_matrix
      private
      public :: linmat
      contains
      subroutine linmat01( mat, y, rxt, het_rates )
!----------------------------------------------
! ... linear matrix entries for implicit species
!----------------------------------------------
      use chem_mods, only : gas_pcnst, rxntot, nzcnt
      use shr_kind_mod, only : r8 => shr_kind_r8
      implicit none
!----------------------------------------------
! ... dummy arguments
!----------------------------------------------
      real(r8), intent(in) :: y(gas_pcnst)
      real(r8), intent(in) :: rxt(rxntot)
      real(r8), intent(in) :: het_rates(max(1,gas_pcnst))
      real(r8), intent(inout) :: mat(nzcnt)
         mat(1) = -( rxt(1) + rxt(3) + het_rates(1) )
         mat(3) = -( het_rates(2) )
         mat(4) = rxt(4)
         mat(5) = -( rxt(4) + het_rates(3) )
         mat(6) = rxt(5) + .500_r8*rxt(6) + rxt(7)
         mat(7) = -( rxt(5) + rxt(6) + rxt(7) + het_rates(4) )
         mat(8) = -( het_rates(5) )
         mat(9) = -( het_rates(6) )
         mat(10) = -( het_rates(7) )
         mat(11) = -( het_rates(8) )
         mat(12) = -( het_rates(9) )
         mat(13) = -( het_rates(10) )
         mat(14) = -( het_rates(11) )
         mat(15) = -( het_rates(12) )
         mat(16) = -( het_rates(13) )
         mat(17) = -( het_rates(14) )
         mat(18) = -( het_rates(15) )
         mat(19) = -( het_rates(16) )
         mat(20) = -( het_rates(17) )
         mat(21) = -( het_rates(18) )
         mat(22) = -( het_rates(19) )
         mat(23) = -( het_rates(20) )
         mat(24) = -( het_rates(21) )
         mat(2) = rxt(3)
      end subroutine linmat01
      subroutine linmat( mat, y, rxt, het_rates )
!----------------------------------------------
! ... linear matrix entries for implicit species
!----------------------------------------------
      use chem_mods, only : gas_pcnst, rxntot, nzcnt
      use shr_kind_mod, only : r8 => shr_kind_r8
      implicit none
!----------------------------------------------
! ... dummy arguments
!----------------------------------------------
      real(r8), intent(in) :: y(gas_pcnst)
      real(r8), intent(in) :: rxt(rxntot)
      real(r8), intent(in) :: het_rates(max(1,gas_pcnst))
      real(r8), intent(inout) :: mat(nzcnt)
      call linmat01( mat, y, rxt, het_rates )
      end subroutine linmat
      end module mo_lin_matrix
