anchor.diff:              call get_lattice(lua_state, sys, opts)
               ! [todo] - deallocate existing basis info and start afresh.
               call init_system(sys)
  +            if (parent) call check_sys(sys)
               call init_model_basis_fns(sys)
               call init_generic_system_basis(sys)
               call init_real_space(sys)
  
positive.code:             ! [todo] - deallocate existing basis info and start afresh.
  
              call init_system(sys)
              call init_model_basis_fns(sys)
              call init_generic_system_basis(sys)
              call init_momentum_symmetry(sys)
  
negative.code:             ! [todo] - deallocate existing basis info and start afresh.
  
              call init_system(sys)
              if (parent) call check_sys(sys)
              call read_in_integrals(sys, cas_info=sys%cas)
              call init_generic_system_basis(sys)
              call print_pg_symmetry_info(sys)
  