Lattice and Orbital-Resolved Fermiology of Metallenes

TL;DR

This study provides a comprehensive analysis of the electronic structures of 45 elemental metallenes, revealing how lattice type and buckling influence their Fermi surfaces, and introduces a predictive 'pocketness' score for applications.

Contribution

It offers the first systematic, detailed electronic-structure characterization of a broad range of metallenes, introducing the 'pocketness' score for predicting their properties.

Findings

Lattice type determines Fermi-line shape and placement.

Buckling modifies Fermi-line segments and pockets.

The 'pocketness' score predicts electronic behavior and guides experiments.

Abstract

Atomically thin metallenes have emerged as a new member of the two-dimensional (2D) materials family. Recent experimental realization of metallenes in the {\AA}ngstr\"om limit has further intensified interest in this class of 2D materials. However, achieving sub-atomic insight into them demands the most detailed and systematic characterization of their electronic structure. Such understanding is essential for the rational design and exploitation of their properties in plasmonics, catalysis, and quantum optics. Existing electronic-structure studies are either scattered or focus on a few selected systems, and a comprehensive view of their band structures and Fermi surfaces remains missing. Here, we address this gap by studying 45 elemental metallenes in six monolayer lattices (honeycomb, square, hexagonal, and their buckled forms) using density-functional theory. We found that lattice type primarily fixes the shape and radial placement of the Fermi-lines, while out-of-plane buckling introduces controlled modifications: it shortens long straight Fermi-line segments, and occasionally creates, removes, or merges small Fermi-line pockets. The electronic configuration determines which orbital type dominates the Fermi level. We summarized Fermiology using a single score for each element, termed pocketness, derived from four descriptors that combine element properties (symmetry, coordination) with electronic characteristics (dispersion, Fermi-surface topology). This score enables targeted angle-resolved photoemission spectroscopy (ARPES) tests, controlled Lifshitz transitions, and provides a predictive basis for transport and device applications.