httk.atomistic.models.formula.api

The minimal canonical chemical-formula interface for httk-atomistic.

Classes

ChemicalFormulaAPI

Abstract base class for the canonical chemical-formula interface.

Module Contents

class httk.atomistic.models.formula.api.ChemicalFormulaAPI

Bases: abc.ABC

Abstract base class for the canonical chemical-formula interface.

The concrete defaults keep backends that do not have provenance for optional formula metadata interoperable without requiring them to implement every accessor.

property amounts: tuple[tuple[str, fractions.Fraction], Ellipsis]

Abstractmethod:

Ordered (label, exact amount) pairs for this chemical formula.

Labels are element symbols in alphabetical order unless is_anonymous, in which case they are OPTIMADE anonymous symbols in canonical (descending-coefficient) order.

property is_anonymous: bool

Whether the formula labels are OPTIMADE anonymous symbols.

A backend that carries anonymous notation overrides this; a backend without that distinction inherits False.

property uncertainties: tuple[tuple[str, fractions.Fraction | None], Ellipsis]

Per-amount absolute uncertainties, or None where exactness is unstated.

property complete: bool

Whether the formula accounts for all represented elemental material.

property exact: bool

Whether all formula amounts are exact rather than precision-bounded.

property normalized: bool

Whether the formula is normalized within the stated precision.

property normalization_status: str

The formula’s normalization status derived from exactness and normalization.

property diagnostics: tuple[httk.atomistic.models.formula.diagnostics.CompositionDiagnostic, Ellipsis]

Non-fatal structured diagnostics associated with the formula.