httk.atomistic.models.cell.params¶

Backend wrapping cell parameters (a, b, c, alpha, beta, gamma).

Classes¶

CellParams

Backend for a cell backed by cell parameters (a, b, c, alpha, beta, gamma).

Module Contents¶

class httk.atomistic.models.cell.params.CellParams(obj, **hints)[source]¶

Bases: httk.atomistic.models.cell.backend.CellBackend

Backend for a cell backed by cell parameters (a, b, c, alpha, beta, gamma).

The native representation is a flat length-6 vector-like of the cell-vector lengths a/b/c and the angles alpha/beta/gamma in degrees, stored as exact Fraction values (parsed via any_to_fraction()). The exact basis is derived lazily and cached using the standard crystallographic orientation convention (first cell vector along x, second in the xy-plane); for the common Niven angles it is exact (radicals intact). Since parameters carry no separate length factor, scale is the exact 1 and unscaled_basis == basis. Parameters carry neither orientation nor periodicity, so a cell → parameters → cell round-trip reproduces lengths and angles, and reproduces volume only for a fully periodic source. Reconstruction uses the fully periodic default and therefore discards any non-3D periodicity as well as the original orientation. unwrap returns the original raw object.