• full name: tenpy.networks.mps.build_initial_state

  • parent module: tenpy.networks.mps

  • type: function

tenpy.networks.mps.build_initial_state(size, states, filling, mode='random', seed=None)[source]

Build an “initial state” list.

Uses two iterables (‘states’ and ‘filling’) to determine how to fill the state. The two lists should have the same length as every element in ‘filling’ gives the filling fraction for the corresponding state in ‘states’.


size = 6, states = [0, 1, 2], filling = [1./3, 2./3, 0.] n_states = size * filling = [2, 4, 0] ==> Two sites will get state 0, 4 sites will get state 1, 0 sites will get state 2.


Make more general: it should be possible to specify states as strings.

  • size (int) – length of state

  • states (iterable) – Containing the possible local states

  • filling (iterable) – Fraction of the total number of sites to get a certain state. If infinite fractions (e.g. 1/3) are needed, one should supply a fraction (1./3.)

  • mode (str | None) – State filling pattern. Only ‘random’ is implemented

  • seed (int | None) – Seed for random number generators


initial_state (list)

Return type:

the initial state

  • ValueError – If fractional fillings are incommensurate with system size.

  • AssertionError – If the total filling is not equal to 1, or the length of filling does not equal the length of states.