Table 2. Criteria used to set structure-assignment reliability score.

Score = 0 if any of:

Unbalanced charges: charges on atoms do not sum to zero over unit cell.

Unprecedented atoms: atom has assignment never observed in CSD (unknown atom-property option).

Unprecedented bonds: bond has type never observed in CSD (unknown bond-type option).

Double-bonded C(ar): C atom forms both aromatic and double bonds.

Score = 1 if none of the above and any of:

Low-probability atoms: an accepted atom-property option has probability 0.01.

Low-probability bonds: an accepted bond-type option has probability 0.01 (excluding bonds in common solvate molecules).

Discrepant metalmetal bond order: assigned metalmetal bond order differs from that calculated by electron counting by > 0.5.

Low probability oxidation state: template-method gives oxidation state with probability 0.1 for at least one metal atom.

Oxidation-state discrepancy: for at least one metal atom, template and BVS methods give oxidation states differing by > 0.99 (test omitted if BVS estimate is of low probability).

Oxidation state could not be calculated: oxidation state of at least one metal atom could not be calculated by template method (e.g. because of missing template).

(X)H missing from large molecule: assignment indicates at least one (X)H atom (X C) missing from a molecule with > 9 non-H atoms (or any molecule if all in unit cell have 18 non-H atoms).

H atom added to planar atom: assignment requires an H atom to be added to an atom already bonded to three atoms in a trigonal geometry.

H atom added to linear atom: assignment requires an H atom to be added to an atom already bonded to 2 atoms in a linear geometry.

Group 1 or 2 metal present.

Score = 2 if none of the above and any of:

Non-planar double or aromatic bond: torsion angle > 20 from planarity.

Difficult substructure present: e.g. tetrathiafulvalene (forms charge-transfer complexes), metal-bound alkoxide (protonation state difficult to determine).

(C)H missing from large molecule: assignment indicates at least one (C)H atom missing from a molecule with > 9 non-H atoms (or any molecule if all in unit cell have 18 non-H atoms).

Charges assigned: two or more atoms assigned non-zero charges.

Metal present.

Score = 3 if none of the above.