Multicomponent methods are a conceptually simple way to include nuclear quantum effects into quantum chemistry calculations. In multicomponent methods, the electronic molecular orbitals are described using the linear combination of atomic orbitals approximation. This requires the selection of a one-particle electronic basis set which, in practice, is commonly a correlation-consistent basis set. In multicomponent method studies, it has been demonstrated that large electronic basis sets are required for quantum hydrogen nuclei to accurately describe electron-nuclear correlation. However, as we show in this study, much of the need for large electronic basis sets is due to the correlation-consistent electronic basis sets not being optimized to describe nuclear properties and electron-nuclear correlation. Herein, we introduce a series of correlation-consistent electronic basis sets for hydrogen atoms called cc-pVnZ-mc with additional basis functions optimized to reproduce multicomponent density functional theory protonic densities. These new electronic basis sets are shown to yield better protonic densities with fewer electronic basis functions than the standard correlation-consistent basis sets and reproduce other protonic properties such as proton affinities and protonic excitation energies, even though they were not optimized for these purposes. The cc-pVnZ-mc basis sets should enable multicomponent many-body calculations on larger systems due to the improved computational efficiency they provide for a given level of accuracy.
Nuclear-Electronic Orbital Multireference Configuration Interaction for Ground and Excited Vibronic States and Fundamental Insights into Multicomponent Basis Sets
The Evolution of Multicomponent Systems at High Pressures: VI. The Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of Hydrocarbons and the Origin of Petroleum
Engineering NV Centers via Hydrogen-Driven Defect Chemistry in CVD Diamonds for Quantum Applications: NVHx Dissociations into NV, Origin of 468nm Center, and Cause of Brown Coloration
CRAHCN-O: A Consistent Reduced Atmospheric Hybrid Chemical Network Oxygen Extension for Hydrogen Cyanide and Formaldehyde Chemistry in CO2-, N2-, H2O-, CH4-, and H2-Dominated Atmospheres
氰化氢（HCN）和甲醛（H2 CO）是行星大气中生成核碱基和氨基酸等生物分子的重要前体物质，然而，在含有CO2和H2O的大气中产生和破坏这些物质的许多反应在文献中仍然缺失。在BHandHLYP/aug-cc-pVDZ理论水平上，利用正则变分过渡态理论和Rice-Ramsperger-Kassel-Marcus/主方程理论，利用量子化学方法找到了这些缺失的反应，并计算了它们的速率系数.我们计算了126个总反应的速率系数，并通过与实验数据进行比较，在39%的可用情况下，验证我们的计算。我们计算的速率系数最经常在实验值的2倍之内，并且通常总是在这些值的一个数量级之内。我们发现了45个以前未知的反应，并确定6从这个列表中，最有可能主导H2 CO和HCN的生产和销毁行星大气。我们强调$^1$ O + CH 3 $\rightarrow$ H2 CO + H作为一个新的关键源，和H2 CO + $^1$ O $\rightarrow$ HCO + OH作为一个新的关键汇，在行星大气上部的H2 CO。在这项工作中，我们开发了一个氧气扩展到我们的一致减少大气混合化学网络（CRAHCN-O），建立了我们以前开发的网络HCN生产在N2，CH 4和H2占主导地位的气氛（CRAHCN）。该扩展可用于模拟由CO2、N2、H2O、CH 4和H2中的任一种主导的气氛中的HCN和H2 CO的产生。
Chemistry on quantum computers with virtual quantum subspace expansion
在量子计算机上模拟化学系统仅限于最小基础上的几个电子。我们通过实验证明，虚拟量子子空间展开[Phys. Rev. X 10，011004（2020）]可以实现氢和锂二聚体的完全基精度，与需要20个或更多量子位的模拟相当。我们开发了一种方法来最大限度地减少实验噪声对广义本征值问题稳定性的影响，广义本征值问题是量子算法的关键组成部分。此外，我们能够获得一个准确的势能曲线的氮二聚体在量子模拟在经典计算机上。
Lattice Density-Functional Theory for Quantum Chemistry
我们提出了一个晶格密度泛函理论{ \it ab initio}量子化学或物理作为一个有效的方法，近似的全组态相互作用能和轨道职业的强关联电子的分子的路线。我们建立在晶格密度泛函理论的哈伯德模型，通过推导一个减少，然后完全量子化学哈密顿的Kohn-Sham方程，并展示了具有挑战性的问题，建模拉长键的六个氢原子的线性链的势能曲线的方法。在这里的准确性的Bethe-anonymous局域密度近似的量子化学系统进行了测试，我们发现，尽管这个近似的功能被设计为哈伯德模型，势曲线的形状一般同意全组态相互作用的结果。虽然对于非常拉伸的键存在差异，但这低于使用局域密度近似的标准密度泛函理论。
