qdk_chemistry.data._spin_channels module

Internal per-spin-channel helpers over symmetry-blocked data.

These helpers are not part of the public API. User code should read symmetry-blocked tensors and index sets through their primitive accessors (SymmetryBlockedTensor.block([...]) and SymmetryBlockedIndexSet.indices(SymmetryLabel([...]))) with explicit SymmetryLabel values.

They exist only for internal library and test use, where they additionally encapsulate the trivial (spin-free) vs spin-resolved label selection so the same call works for restricted, unrestricted, and model (symmetry-free) orbitals.

qdk_chemistry.data._spin_channels.spin_channel_indices(index_set: qdk_chemistry.data.symmetry.SymmetryBlockedIndexSet, channel: qdk_chemistry.data.symmetry.SpinValue) → list[int]

Indices for a single spin channel of a SymmetryBlockedIndexSet as a flat list. Pass the channel explicitly, e.g. axes.alpha() or axes.beta(); for a spin-free set the sole trivial-label segment serves every channel. Returns an empty list when ‘index_set’ is None.

qdk_chemistry.data._spin_channels.spin_channel_matrix(coefficients, channel)[source]

Per-spin dense block of a rank-2 (coefficient-like) SymmetryBlockedTensor.

Returns the block for channel; for a restricted (spin-equivalent) tensor the alpha and beta blocks share storage, so either channel selection succeeds.

Parameters:

  • coefficients (SymmetryBlockedTensorRank2) – A rank-2 SymmetryBlockedTensor (e.g. orbital coefficients).

  • channel (SpinValue) – The spin channel to select, e.g. axes.alpha() or axes.beta().

Returns:

The requested spin channel’s dense block as a NumPy array.

qdk_chemistry.data._spin_channels.spin_channel_vector(energies, channel)[source]

Per-spin dense block of a rank-1 (energy-like) SymmetryBlockedTensor.

Returns the block for channel; for a restricted (spin-equivalent) tensor the alpha and beta blocks share storage, so either channel selection succeeds.

Parameters:

  • energies (SymmetryBlockedTensorRank1) – A rank-1 SymmetryBlockedTensor (e.g. orbital energies).

  • channel (SpinValue) – The spin channel to select, e.g. axes.alpha() or axes.beta().

Returns:

The requested spin channel’s dense block as a NumPy array.