Minor tally derivative cleanup

src/input_xml.F90

@@ -947,7 +947,6 @@ contains
     type(XMLNode), allocatable :: node_tal_list(:)
     type(XMLNode), allocatable :: node_filt_list(:)
     type(XMLNode), allocatable :: node_trigger_list(:)
-    type(XMLNode), allocatable :: node_deriv_list(:)
     type(DictEntryCI) :: elem
     type(TallyDerivative), pointer :: deriv
 
@@ -1004,11 +1003,6 @@ contains
 
     call read_tally_derivatives(root % ptr)
 
-    do i = 0, n_tally_derivs() - 1
-      deriv => tally_deriv_c(i)
-      call tally_deriv_dict % set(deriv % id, i)
-    end do
-
     ! ==========================================================================
     ! READ FILTER DATA
 

src/tallies/derivative.cpp

@@ -102,14 +102,12 @@ read_tally_derivatives(pugi::xml_node* node)
     fatal_error("Differential tallies not supported in multi-group mode");
 }
 
-/*
 //! Set the flux derivatives on differential tallies to zero.
 extern "C" void
-zero_flux_derivs_c()
+zero_flux_derivs()
 {
   for (auto& deriv : model::tally_derivs) deriv.flux_deriv = 0.;
 }
-*/
 
 //==============================================================================
 // Fortran interop

src/tallies/tally.F90

@@ -46,6 +46,11 @@ module tally
     end subroutine score_analog_tally_
   end interface
 
+  interface
+    subroutine zero_flux_derivs() bind(C)
+    end subroutine
+  end interface
+
 contains
 
 !===============================================================================
@@ -3713,19 +3718,6 @@ contains
     end do
   end subroutine score_collision_derivative
 
-!===============================================================================
-! ZERO_FLUX_DERIVS Set the flux derivatives on differential tallies to zero.
-!===============================================================================
-
-  subroutine zero_flux_derivs()
-    integer :: i
-    type(TallyDerivative), pointer :: deriv
-    do i = 0, n_tally_derivs() - 1
-      deriv => tally_deriv_c(i)
-      deriv % flux_deriv = ZERO
-    end do
-  end subroutine zero_flux_derivs
-
 !===============================================================================
 ! ACCUMULATE_TALLIES accumulates the sum of the contributions from each history
 ! within the batch to a new random variable

src/tallies/tally_derivative_header.F90

@@ -2,8 +2,6 @@ module tally_derivative_header
 
   use, intrinsic :: ISO_C_BINDING
 
-  use dict_header, only: DictIntInt
-
   implicit none
 
 !===============================================================================
@@ -19,9 +17,6 @@ module tally_derivative_header
     real(C_DOUBLE) :: flux_deriv
   end type TallyDerivative
 
-  ! Dictionary that maps user IDs to indices in 'tally_derivs'
-  type(DictIntInt), public :: tally_deriv_dict
-
   interface
     function n_tally_derivs() result(n) bind(C)
       import C_INT