A few functions use unrounded float as dict keys

[DanielYang59]

Using float as dict keys can be prone to precision issues (especially when float is not rounded), a few functions operate on such dict[float, Any] (could be more not annotated):

core.bonds.obtain_all_bond_lengths

pymatgen/src/pymatgen/core/bonds.py

Lines 122 to 137 in bd9fba9

	def obtain_all_bond_lengths(
	sp1: SpeciesLike,
	sp2: SpeciesLike,
	default_bl: float | None = None,
	) -> dict[float, float]:
	"""Obtain bond lengths for all bond orders from bond length database.
	Args:
	sp1 (Species): First specie.
	sp2 (Species): Second specie.
	default_bl: If a particular type of bond does not exist, use this
	bond length as a default value (bond order = 1).
	If None, a ValueError will be thrown.
	Returns:
	A dict mapping bond order to bond length in angstrom

core.lattice.Lattie

pymatgen/src/pymatgen/core/lattice.py

Lines 545 to 557 in bd9fba9

	@property
	def lll_matrix(self) -> np.ndarray:
	"""The matrix for LLL reduction."""
	if 0.75 not in self._lll_matrix_mappings:
	self._lll_matrix_mappings[0.75] = self._calculate_lll()
	return self._lll_matrix_mappings[0.75][0]
	@property
	def lll_mapping(self) -> np.ndarray:
	"""The mapping between the LLL reduced lattice and the original lattice."""
	if 0.75 not in self._lll_matrix_mappings:
	self._lll_matrix_mappings[0.75] = self._calculate_lll()
	return self._lll_matrix_mappings[0.75][1]

diffraction patterns

pymatgen/src/pymatgen/analysis/diffraction/neutron.py

Line 135 in bd9fba9

peaks: dict[float, list[float | list[tuple[int, ...]]]] = {}

pymatgen/src/pymatgen/analysis/diffraction/xrd.py

Line 199 in bd9fba9

peaks: dict[float, list[float | list[tuple[int, ...]]]] = {}