Tools

split_work(N, comm, split_method)
split_work(N, N_comm, my_rank, split_method)

Distribute N work items across MPI ranks. Returns a vector of indices assigned to this rank. Available strategies:

• DefaultSplit() — balanced distribution with remainder spread across the first ranks.
• FHIaimsLAPACKSplit() — round-robin distribution matching FHI-aims' LAPACK work split.

get_frac_positions(atoms) -> Matrix

Return atom positions in fractional coordinates (unitless). Each column is one atom.

get_images(atoms) -> Matrix

Return periodic images to which each atom belongs. Each column is one atom.

get_real_lattice(atoms) -> Matrix

Return the real-space lattice as a matrix with basis vectors as columns.

get_recip_lattice(atoms_or_real_lattice) -> Matrix

Return the reciprocal-space lattice satisfying AᵀB = 2πI, with basis vectors as columns.

get_species2atom(atoms) -> Dictionary

Return a dictionary mapping each unique ChemicalSpecies to the vector of atom indices of that species.

recentre(atoms) -> AbstractSystem

Wrap atom positions into the unit cell centred at [0.5, 0.5, 0.5] in fractional coordinates. Only supports fully periodic systems. Returns a new system with recentred positions.

convert_to_atomarray(dict, atom2species_or_natoms)

Convert a species-keyed or atom-pair-keyed dictionary to a flat array (or matrix) indexed by atom index. Missing entries are filled with a sentinel value. Used to convert dictionary lookups to array indexing in performance-critical loops.

get_spglib_cell(atoms) -> Spglib.Cell

Convert an AbstractSystem to an Spglib Cell for symmetry analysis.

get_symmetry_rotations(spglib_cell; crystal_symmetry=false, symprec=1e-5)

Return point-group rotation matrices. If crystal_symmetry=false, returns only the identity. Otherwise, queries Spglib for the full set of crystal symmetry rotations.