Left/right handedness assignment to chiral tetrahedral AB₄ structures

Chiral tetrahedral AB₄ molecules or molecular fragments, where A and B are atoms, are common, yet handedness assignment rules for these species, to the best of our knowledge, do not exist. We propose a simple set of rules for such an assignment and apply it to many chiral molecules; to a chiral crystal-quartz-identifying preservation of handedness across its phase transition; and to a large random population of chiral AB₄ structures. The concept of handedness-labelling is discussed by presenting a second alternative for labelling.