result_send Subroutine

   subroutine result_send(result, comm, dest, tag)
      !! Send calculation result over MPI (blocking)
      !! Sends energy components and conditionally sends gradient based on has_gradient flag
      type(calculation_result_t), intent(in) :: result
      type(comm_t), intent(in) :: comm
      integer, intent(in) :: dest, tag

      ! Send energy components
      call send(comm, result%energy%scf, dest, tag)
      call send(comm, result%energy%mp2%ss, dest, tag)
      call send(comm, result%energy%mp2%os, dest, tag)
      call send(comm, result%energy%cc%singles, dest, tag)
      call send(comm, result%energy%cc%doubles, dest, tag)
      call send(comm, result%energy%cc%triples, dest, tag)

      ! Send fragment metadata
      call send(comm, result%distance, dest, tag)

      ! Send gradient flag and data if present
      call send(comm, result%has_gradient, dest, tag)
      if (result%has_gradient) then
         call send(comm, result%gradient, dest, tag)
      end if

      ! Send Hessian flag and data if present
      call send(comm, result%has_hessian, dest, tag)
      if (result%has_hessian) then
         call send(comm, result%hessian, dest, tag)
      end if

      ! Send dipole flag and data if present
      call send(comm, result%has_dipole, dest, tag)
      if (result%has_dipole) then
         call send(comm, result%dipole, dest, tag)
      end if

      ! Send dipole derivatives flag and data if present
      call send(comm, result%has_dipole_derivatives, dest, tag)
      if (result%has_dipole_derivatives) then
         call send(comm, result%dipole_derivatives, dest, tag)
      end if
   end subroutine result_send