论文标题
LASCO的多体电子结构$ _3 $由真实空间量子蒙特卡洛
Many-body electronic structure of LaScO$_3$ by real space quantum Monte Carlo
论文作者
论文摘要
我们介绍了丑闻lasco $ _3 $的真实空间量子蒙特卡洛（QMC）计算，与现有实验数据相比，由于强大的相关效应，这对于传统电子结构方法而言是挑战的，导致DFT和$ GW $方法的频段差距不准确。除了计算出针对超级细胞大小偏差的精确QMC带隙并与许多实验一致之外，我们还使用标准的固定节点QMC预测了晶体的内聚能，而无需任何经验或非差异参数。我们表明，促进（光学）间隙和基本差距彼此一致，这说明了理想晶体中显然没有明显的激子效应。我们在使用不同的基集（平面波与局部高斯人）的两个独立轨道中获得了完美的一致性，我们获得了这些结果，生成轨道的不同代码（\ textsc {Quantum pesso} vs. \ textsc {crystal}），不同（CCECPS与Troullier-Martins）介绍QMC方法论的成熟度和一致性，以及用于研究密切相关问题的工具。
We present real space quantum Monte Carlo (QMC) calculations of the scandate LaScO$_3$ that proved to be challenging for traditional electronic structure approaches due to strong correlation effects resulting in inaccurate band gaps from DFT and $GW$ methods when compared with existing experimental data. Besides calculating an accurate QMC band gap corrected for supercell size biases and in agreement with numerous experiments, we also predict the cohesive energy of the crystal using the standard fixed-node QMC without any empirical or non-variational parameters. We show that promotion (optical) gap and fundamental gap agree with each other illustrating a clear absence of significant excitonic effects in the ideal crystal. We obtained these results in perfect consistency in two independent tracks that employ different basis sets (plane wave vs. localized gaussians), different codes for generating orbitals (\textsc{Quantum Espresso} vs. \textsc{Crystal}), different QMC codes (\textsc{Qmcpack} vs. \textsc{Qwalk}) and different high-accuracy pseudopotentials (ccECPs vs. Troullier-Martins) presenting the maturity and consistency of QMC methodology and tools for studies of strongly correlated problems.
