# 4.1. tkwant.system – Tools for time-dependent and open Kwant systems¶

 add_time_to_params(params, time_name, time) Add a time_name: time key-value pair to a params dict. is_time_dependent_function(obj, time_name) Return True if obj is callable and has a time argument orb_range(syst, site) Return the first orbital of this and the next site. ExtendedSystem(syst, H0, boundary_slices, …) Hamiltonian matrix of central system + boundary conditions.