Operators

default_shconv(source) -> SHConvention

Return the default spherical harmonics convention for the given source. Memoized.

get_z1z2_ij2interval(atoms_or_metadata_or_operator)
get_z1z2_ij2interval(atoms, sparsity)

Compute a species-pair-keyed dictionary mapping each (z₁, z₂) pair to an ordered dictionary of (i, j) => UnitRange intervals. The intervals index contiguously into the third dimension of the canonical block-real data array for that species pair. Used internally to lay out and access per-image data slices.