eigenbasis

property Model.eigenbasis: ndarray | Array | None

Eigenstates of static_hamiltonian expressed in the product basis.

The returned array contains one eigenstate per row, written in the product basis defined by basis. The row ordering is not the raw order returned by the eigensolver. Instead, Simphony relabels the eigensystem with a one-to-one assignment that maximizes the total overlap between eigenstates and local-\(S_z\) product-basis states. This makes the eigenbasis easier to interpret in common weak-mixing situations, where each eigenstate is still dominated by a single product-basis component.

In strongly mixed, degenerate, or nearly degenerate cases, the assigned local-\(S_z\) product-basis labels should be understood as a practical naming convention rather than as an exact statement about state identity. Use test_labeling() to inspect the overlap structure explicitly when label interpretation matters.

Returns:

Array of shape (dimension, dimension) whose i-th row is the eigenstate currently labelled by basis[i].