Multi-product formulas (MPF) release notes

---

0.3.0

New Features

• TeNPy can disable Sz conservation. Previously, the initialize_from_lattice() method did not support this, but a new keyword argument conserve has been added which allows the disabling of Sz conservation. The default remains to be True.

• Guards against unexpected behavior when N_steps != 1 in qiskit_addon_mpf.backends.tenpy_layers.LayerwiseEvolver.evolve().

Upgrade Notes

• This release adds support for Python 3.13. No code changes were necessary, so older releases are expected to work on Python 3.13 too.

• This package is now compatible with Qiskit SDK 2.0.

• The keep_only_odd attribute of quimb_layers.LayerModel has been removed. The internal workings have been refactored to ensure that data reported by its terms attribute (which is inherited from the base class) is already taking the keep_only_odd argument of the quimb_layers.LayerModel.from_quantum_circuit() constructor method.

• The scaling_factor keyword argument of the from_quantum_circuit constructor methods has been removed. It is not actually needed and was merely adding an additional (confusing) re-scaling.

Bug Fixes

• Fixes the DynamicMPF.evolve() method when providing time values with numerical inaccuracies (e.g. time=1.00000001). Previously this could cause the LHS and RHS time evolvers to advance too far. The new default accuracy is 8 decimal places, but it may be configured via the DynamicMPF.TIME_DECIMALS value.

---

0.2.0

New Features

• Adds the ability to compute dynamic (i.e. time-dependent) MPF coefficients. For more details, refer to qiskit_addon_mpf.dynamic.

Upgrade Notes

• The code for the static MPF coefficients has been moved. It functions the same as before, but you have to update your imports and function names as summarized in the table below:

  Old	New
  from qiskit_addon_mpf.static import setup_lse	from qiskit_addon_mpf.static import setup_static_lse
  from qiskit_addon_mpf.static import LSE	from qiskit_addon_mpf.costs import LSE
  from qiskit_addon_mpf.static import setup_exact_model	from qiskit_addon_mpf.costs import setup_exact_problem
  from qiskit_addon_mpf.static import setup_approximate_model	from qiskit_addon_mpf.costs import setup_sum_of_squares_problem