Electronic structure of bulk manganese oxide and nickel oxide from coupled cluster theory
Electronic structure of bulk manganese oxide and nickel oxide from coupled cluster theory
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从耦合簇理论研究大块氧化锰和氧化镍的电子结构
DOI：
10.1103/physrevb.101.165138
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发表时间：
2019
影响因子：
3.7
通讯作者：
G. Chan
中科院分区：
文献类型：
--
作者：
Yang Gao;Qiming Sun;Jason M. Yu;M. Motta;James D. McClain;Alec F. White;A. Minnich;G. Chan
本文利用单激发和双激发耦合簇理论（CCSD），描述了两种典型相关电子材料MnO和NiO的基态和激发态电子结构。作为一个推论，这项工作也报道了第一个无限制周期从头开始运动方程CCSD的实现。从hartrei - fock参考文献开始，我们发现16个单元超级单体的MnO和NiO的基本间隙分别为3.46 eV和4.83 eV，与实验相比略微高估，尽管有限尺寸缩放表明热力学极限下的间隙被严重高估。从相关电子带的特征来看，我们发现MnO和NiO都处于中间Mott/电荷转移绝缘子区，尽管NiO在仅考虑基隙时表现为电荷转移绝缘子。虽然在大部分布里温区，最低的准粒子激发为金属3d和o2p特征，但在Γ点附近，最低的准粒子激发为s特征。我们的研究支持耦合簇理论的潜力，为相关固体提供高水平的多体洞察。
We describe the ground- and excited-state electronic structure of bulk MnO and NiO, two prototypical correlated electron materials, using coupled cluster theory with single and double excitations (CCSD). As a corollary, this work also reports the first implementation of unrestricted periodic ab initio equation-of motion CCSD. Starting from a Hartree-Fock reference, we find fundamental gaps of 3.46 eV and 4.83 eV for MnO and NiO respectively for the 16 unit supercell, slightly overestimated compared to experiment, although finite-size scaling suggests that the gap is more severely overestimated in the thermodynamic limit. From the character of the correlated electronic bands we find both MnO and NiO to lie in the intermediate Mott/charge-transfer insulator regime, although NiO appears as a charge transfer insulator when only the fundamental gap is considered. While the lowest quasiparticle excitations are of metal 3d and O 2p character in most of the Brillouin zone, near the Γ point, the lowest conduction band quasiparticles are of s character. Our study supports the potential of coupled cluster theory to provide high level many-body insights into correlated solids.