Struct ShellPairData 

pub struct ShellPairData { /* private fields */ }

Precomputed, screened [PrimPair] list of one ordered shell pair — libcint’s pair-data (“optimizer”) precompute. A dense driver builds one per canonical shell pair once per build (O(n_shells²), trivial memory) and passes borrowed lists to coulomb_shell_pairs_into_scratch / coulomb_shell_batch4_pairs_into_scratch, instead of the engine rebuilding the same pairs on every quartet that shares the pair.

The contents and order are exactly what the self-building entries compute internally ([build_pairs]), so routing through borrowed lists is bit-identical. Orientation matters: build_pairs(s1, s2) is order-sensitive (r1 = P − A uses s1’s centre; c1/c2 keep the s1-outer/s2-inner coefficient association), so a list built for (i, j) must only be used where the engine would have built (i, j) — the canonical drivers use the i ≥ j orientation for both bra and ket throughout.

Implementations

impl ShellPairData

pub fn len(&self) -> usize

Number of surviving primitive pairs (the [PAIR_NEGLIGIBLE] screen applied) — what surviving_pair_count returns for the same pair.

pub fn is_empty(&self) -> bool

true when no primitive pair survives the negligibility screen.

Trait Implementations

impl Clone for ShellPairData

fn clone(&self) -> ShellPairData

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ShellPairData

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ShellPairData

fn default() -> ShellPairData

Returns the “default value” for a type.