Also called dicalcium nitride, 2D electride
A crystal whose anion is a layer of electrons. In Ca2N the space between the calcium–nitrogen layers contains no atoms, just a two-dimensional electron gas that is part of the chemical formula. That gives a metal with unusually loosely bound electrons and a low work function, and it can be exfoliated, so the electron layer can be studied as a free-standing 2D material rather than only inside a bulk crystal.
They are coordination polyhedra. Only complete ones are drawn.
Three layers of Ca2N. Each layer is shifted by the same step in the same direction, so the pattern repeats only after three layers: c = 18.97 Å. The gaps between the layers hold no atoms, only the sheets of electrons that make Ca2N an electride. Cell from Baker, Barker and Blake, Acta Crystallographica E 57, i6 (2001); COD 2200084.
Readiness runs lab → prototype → pilot → deployed.
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An electride is a challenge to the usual band-structure bookkeeping: the electrons in the interlayer space occupy states that belong to no atom, so basis sets and pseudopotentials built around atomic sites need care, and the electron gas must be described as a quantum well between the calcium layers. That layer is genuinely two-dimensional in the bulk, which makes Ca2N an unusual case where reducing the thickness tests whether the confinement was ever three-dimensional. Its low work function and strong reducing power fall straight out of how weakly those electrons are bound.
Air is the enemy: exfoliate, store and measure under nitrogen or argon, and report the solvent, since solvent choice determines whether flakes survive weeks or minutes. Check that the exfoliated material is still Ca2N rather than an oxide or hydroxide by combining diffraction with elemental analysis, and use optical response as a second check that the interlayer electrons are still there.
Not a device material as it stands – it reacts with air and water, which rules out ordinary processing. Its practical interest is as a low-work-function electron source and as a reducing agent in catalysis, both of which tolerate inert handling.
The newest items tagged Ca2N, from the news feed updated 5 Oct 2026.
Electrides, ionic crystals in which excess electrons are delocalized within interstitial voids rather than bound to specific atomic sites, exhibit exotic physicochemical behaviors, yet their potential as electrochemical energy-storage hosts remains largely unexplored. Here, using comprehensive first-principles…
The recent discovery of long-sought dice flat band in layered YCl electride has opened up rich possibilities of correlation and topological physics in dice lattice systems [Nature Communications 17, 2213 (2026), arXiv:2509.05958]. Here, we reveal a plethora of distinctive correlated topological phases in a generic…
Electrides are an unusual class of ionic materials in which electrons localized in non-nuclear, interstitial regions act as anions within the crystal lattice. Here, we employ first-principles quantum mechanical calculations to investigate the structural, electronic, magnetic, and electride characteristics of elemental…
We investigate the magnetic-field response of interstitial anionic electrons (IAEs) in two-dimensional electrides, using monolayer Ca2N as a prototypical system. By computing the Landau-level (LL) spectrum of the electride bands forming the Fermi surface, we find a linear LL evolution with magnetic field that closely…
Electron transport in solids arises primarily from two mechanisms: freely moving bulk electrons in metals, and gapless boundary states in topological insulators. Here, we report a new mechanism discovered in electrides. The topological interstitial-electron conductors (TIECs) proposed here are insulating electrides…
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