anchor.diff:          use symmetry, only: inv_sym
           use basis, only: basis_length
   
  -        integer, intent(in) :: spos
  +        integer, intent(inout) :: spos
           type(det_info), intent(in) :: cdet
   
           real(dp) :: pgen, psuccess, pspawn
  
positive.code:         !    spos: current position within the spawned walkers array.
          !    cdet: info on the current determinant (cdet) that we will spawn
          !        from.
  
          use determinants, only: det_info
          use dSFMT_interface, only:  genrand_real2
  
negative.code:             call create_excited_det(cdet%f, connection, f_new)
              spawned_walker_dets(:,spos) = f_new
              spawned_walker_population(spos) = nparticles
  
              ! Having spawned, move to the next position in the spawning array.
              spos = spos + 1
  
          end if
          
  