anchor.diff:          !   - writing preamble information in log.
   
           use qmc_data, only: logging_t, logging_in_t
  -        use calc, only: calc_type, fciqmc_calc, ccmc_calc
   
           type(logging_t), intent(inout) :: logging_info
           type(logging_in_t), intent(in) :: logging_in
  -        integer :: iunit
   
           open(newunit=logging_info%spawn_unit, file=get_log_filename(logging_in%spawn_filename), &
                   status='unknown')
  
positive.code:         !   - writing preamble information in log.
  
          use qmc_data, only: logging_t, logging_in_t
          use parallel, only: iproc
  
          type(logging_t), intent(inout) :: logging_info
          type(logging_in_t), intent(in) :: logging_in
          integer :: iunit
  
          open(newunit=logging_info%calc_unit, file=get_log_filename(logging_in%calc_filename), &
                  status='unknown')
  
negative.code:         !   - writing preamble information in log.
  
          use qmc_data, only: logging_t, logging_in_t
  
          type(logging_t), intent(inout) :: logging_info
          type(logging_in_t), intent(in) :: logging_in
  
          open(newunit=logging_info%death_unit, file=get_log_filename(logging_in%death_filename), &
                  status='unknown')
  