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arXiv · 2606.15337

A Unified Dielectric-Dependent Hybrid Functional for Accurate Band Gaps across Dimensions

Subrata Jana·Manoar Hossain·Arghya Ghosh·Gabriel Chirchir·Prasanjit Samal·Szymon Smiga
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Abstract

Predicting fundamental band gaps across material classes and dimensionalities remains a central challenge in electronic-structure theory. Here, we show that intrinsic dielectric screening provides a unified control parameter for nonlocal exchange from bulk to low-dimensional and heterogeneous materials. We introduce a geometry-independent dielectric response and incorporate it self-consistently into a nonempirical screened-dielectric-dependent hybrid functional. Benchmarks for 100 materials spanning bulk, two-dimensional, one-dimensional, and mixed-dimensional systems show near-GW accuracy at the computational cost of generalized Kohn-Sham theory. These results reveal a screening-exchange-gap relation in which reduced dimensionality weakens intrinsic dielectric screening, strengthens nonlocal exchange, and drives the opening of fundamental gaps.

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Subrata Jana, Manoar Hossain, Arghya Ghosh, Gabriel Chirchir, Prasanjit Samal, Szymon Smiga. 2026-06-13. A Unified Dielectric-Dependent Hybrid Functional for Accurate Band Gaps across Dimensions. https://arxiv.org/abs/2606.15337

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