mag4.analysis.bond_angles

Bridging-ligand bond-angle analysis (M – L – M).

Functions

compress_angles(ang_vals[, tol])	Group similar angles: [159.07, 159.07, 159.07] → '159.07° (x3)'.
find_bridging_angles(structure, site_i, ...)	Find every ligand L bridging site_i and site_j (at jimage).
find_dihedral_paths(structure, site_i, ...)	Find every M1–L1–L2–M2 super-super-exchange path between site_i (home) and site_j (at jimage).
get_mm_pairs(structure, element, cutoff)	Return sorted list of unique M–M pairs within cutoff Å.
group_into_shells(results[, tol])	Cluster M–M pairs into distance shells (J1, J2, …).
print_angles_for_shell(group, structure, ...)	Bond-angle table for one J shell.
print_header(structure, element, ...)	Print a header summarising the structure and the search parameters.
print_shell_summary(groups, element)	Brief summary of the J shells.
write_report(lines_out, output_file)	Write accumulated report lines to output_file.

mag4.analysis.bond_angles.get_mm_pairs(structure, element, cutoff)

Return sorted list of unique M–M pairs within cutoff Å.

Mirrors mag4.io_cif.get_mm_distances() but returns lighter dicts (no label_* fields) suited to the bond-angle workflow.

Parameters:

• element (str)

• cutoff (float)

mag4.analysis.bond_angles.group_into_shells(results, tol=0.01)

Cluster M–M pairs into distance shells (J1, J2, …).

Parameters:

tol (float)

mag4.analysis.bond_angles.find_bridging_angles(structure, site_i, site_j, jimage, ligand_elements, bond_cutoff)

Find every ligand L bridging site_i and site_j (at jimage).

A ligand L bridges the pair when dist(site_i, L) < bond_cutoff AND dist(site_j + jimage, L) < bond_cutoff.

Returns a list of dicts sorted by angle.

mag4.analysis.bond_angles.find_dihedral_paths(structure, site_i, site_j, jimage, ligand_elements, bond_cutoff, ll_cutoff)

Find every M1–L1–L2–M2 super-super-exchange path between site_i (home) and site_j (at jimage).

A path exists when:

• L1 is bonded to M1 (distance ≤ bond_cutoff);

• L2 is bonded to M2 + jimage (distance ≤ bond_cutoff);

• L1 and L2 are bonded to each other (distance ≤ ll_cutoff);

• L1 and L2 are distinct ligand atoms (otherwise the path is a direct M–L–M bridge already covered by find_bridging_angles()).

The returned dihedral is the signed torsion angle of the four-atom path in degrees, in [-180°, +180°] following the IUPAC convention.

Returns a list of dicts, deduplicated on (L1 identity, L2 identity) and sorted by signed dihedral.

mag4.analysis.bond_angles.compress_angles(ang_vals, tol=0.01)

Group similar angles: [159.07, 159.07, 159.07] → '159.07° (x3)'.

Return type:

str

Parameters:

• ang_vals (List[float])

• tol (float)

mag4.analysis.bond_angles.print_header(structure, element, ligand_elements, cutoff, bond_cutoff)

Print a header summarising the structure and the search parameters.

mag4.analysis.bond_angles.print_shell_summary(groups, element)

Brief summary of the J shells.

mag4.analysis.bond_angles.print_angles_for_shell(group, structure, element, ligand_elements, bond_cutoff, lines_out)

Bond-angle table for one J shell. Appends each printed line to lines_out.

mag4.analysis.bond_angles.write_report(lines_out, output_file)

Write accumulated report lines to output_file.