Abnormal bonding and electronic states in the gap of amorphous solids

Abstract
Localized electronic states lying deep within the forbidden energy gap of an amorphous solid are improbable occurrences associated with distortions for which the energetics appropriate to normally bonded atoms are no longer necessarily applicable. We describe an abnormal bonding model which facilitates the enumeration of these admittedly improbable, but none the less possible, states. A wellcharacterized subset of the highly localized deep gap states possible in groups V, VI, and V-VI amorphous solids is discussed in terms of known experimental facts.