量子化学のシミュレーション精度を向上させる新手法(Quantum chemistry: Making key simulation approach more accurate)

2025-09-19 ミシガン大学

ミシガン大学の研究者は、分子や材料の電子構造を予測する代表的手法 密度汎関数理論(DFT) を高精度化する新アプローチを開発した。DFTは計算効率に優れる一方、電子の交換・相関効果を近似式で処理するため誤差が生じやすい。今回の研究では、多体量子理論による高精度計算をデータとし、逆問題として最適な交換相関汎関数を機械学習で導出。これにより従来より精度の高いシミュレーションが可能になり、誤差低減と計算負荷削減を両立できる可能性が示された。この成果は分子設計、新素材開発、電子デバイス研究など幅広い分野に応用が期待される。

量子化学のシミュレーション精度を向上させる新手法(Quantum chemistry: Making key simulation approach more accurate)
A 3D map of the quantum potential that guides the positions and motions of electrons in lithium hydride. The purple region is least favorable, while the orange is most favorable. The cut-away section shows the centers of the lithium (left) and hydrogen (right) atoms. Image credit: Bikash Kanungo and Paul Zimmerman, University of Michigan

<関連情報>

正確な交換相関ポテンシャルとエネルギーから局所および半局所密度汎関数を学ぶ Learning local and semi-local density functionals from exact exchange-correlation potentials and energies

Bikash Kanungo, Jeffrey Hatch, Paul M. Zimmerman, and Vikram Gavini
Science Advances  Published:19 Sep 2025
DOI:https://doi.org/10.1126/sciadv.ady8962

Abstract

Finding accurate exchange-correlation (XC) functionals remains the defining challenge in density functional theory (DFT). Despite 40 years of active development, attaining general purpose chemical accuracy is still elusive with existing functionals. We present a data-driven pathway to learn the XC functional by using the exact density, XC energy, and XC potential. While the exact densities are obtained from accurate configuration interaction (CI), the exact XC energies and XC potentials are obtained via inverse DFT calculations on the CI densities. We demonstrate how simple neural network (NN)–based local density approximation (LDA) and generalized gradient approximation (GGA), trained on just five atoms and two molecules, provide remarkable improvement in total energies and densities. Particularly, the NN-based GGA functional attains similar accuracy as the higher rung SCAN meta-GGA on various thermochemistry datasets. These results underscore the promise of using the XC potential in modeling XC functionals and can pave the way for systematic learning of increasingly accurate XC functionals.

1603情報システム・データ工学
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