Arsenide

This short distance indicates the complex bonding in these simple phases, i.e. they are not simply salts of As3− anion, for example.

Cadmium arsenide (Cd3As2) was shown to be a three-dimensional (3D) topological Dirac semimetal analogous to graphene.

[1] Assigning formal oxidation numbers is difficult because these materials are highly covalent and often are best described with band theory.

The extraction of the metals – nickel, iron, cobalt, copper – entails chemical processes such as smelting that poses environmental risks.

Partial reduction of arsenic with alkali metals (and related electropositive elements) affords polyarsenic compounds, which are members of the Zintl phases.