Barcza Gergely, Ivády Viktor, Szilvási Tibor, Vörös Márton, Veis Libor, Gali Ádám, Legeza Örs
Wigner Research Centre for Physics, P.O. Box 49, Budapest H-1525, Hungary.
J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague CZ-18223, Czechia.
J Chem Theory Comput. 2021 Feb 9;17(2):1143-1154. doi: 10.1021/acs.jctc.0c00809. Epub 2021 Jan 13.
In this paper, we analyze the numerical aspects of the inherent multireference density matrix renormalization group (DMRG) calculations on top of the periodic Kohn-Sham density functional theory using the complete active space approach. The potential of the framework is illustrated by studying hexagonal boron nitride nanoflakes embedding a charged single boron vacancy point defect by revealing a vertical energy spectrum with a prominent multireference character. We investigate the consistency of the DMRG energy spectrum from the perspective of sample size, basis size, and active space selection protocol. Results obtained from standard quantum chemical atom-centered basis calculations and plane-wave based counterparts show excellent agreement. Furthermore, we also discuss the spectrum of the periodic sheet which is in good agreement with extrapolated data of finite clusters. These results pave the way toward applying the DMRG method in extended correlated solid-state systems, such as point defect qubit in wide band gap semiconductors.
在本文中中我们分析了基于周期Kohn-Sham密度泛函理论、使用完全活性空间方法的固有多参考密度矩阵重整化群（DMRG）计算的数值方面。通过研究嵌入带电单硼空位点缺陷的六方氮化硼纳米片，揭示了具有显著多参考特征的垂直能谱，从而说明了该框架的潜力。我们从样本大小、基组大小和活性空间选择协议的角度研究了DMRG能谱的一致性。从标准量子化学以原子为中心的基组计算和基于平面波的对应计算中获得的结果显示出极好的一致性。此外，我们还讨论了周期薄片的能谱，它与有限团簇的外推数据吻合良好。这些结果为在扩展的相关固态系统中应用DMRG方法铺平了道路，例如宽带隙半导体中的点缺陷量子比特。
