Tenti Lorenzo, Peeters Stefan, Giner Emmanuel, Angeli Celestino
Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Borsari 76, I-44121 Ferrara, Italy.
Fraunhofer IWM, MikroTribologie Centrum μTC, Wöhlerstraße 11, 79108 Freiburg, Germany.
J Chem Theory Comput. 2024 Dec 24;20(24):10861-10874. doi: 10.1021/acs.jctc.4c01101. Epub 2024 Dec 4.
The use of the mutual information (MI) as a measure of the entanglement in quantum systems has gained a consensus in recent years, even if there is an ongoing effort to distinguish the classical and quantum contributions contained therein. This quantity has been first introduced in condensed matter physics, in particular, in studies based on the density matrix renormalization group method. This method has been successfully adapted to quantum chemistry problems, opening the way to compute MI also in molecular systems. A key aspect of this quantity is its dependence on the one-electron (orbital) basis set, even for wave functions that are invariant under unitary transformation of the orbitals. In this work, we investigate the role of the orbital basis set (delocalized or localized, following different strategies) for wave functions expressed as linear combinations of Slater determinants and we give the analytic expression for the MI for a few special cases. This study aims to improve the knowledge of the relationship between the characteristics of the chemical bond (considering a few paradigmatic molecules, H, F, N, and short linear polyenes) and the properties of interest in the field of quantum information theory.
近年来，使用互信息（MI）作为量子系统中纠缠的一种度量已达成共识，即便目前仍在努力区分其中包含的经典和量子贡献。这个量最初是在凝聚态物理中引入的，特别是在基于密度矩阵重整化群方法的研究中。该方法已成功应用于量子化学问题，为在分子系统中计算MI开辟了道路。这个量的一个关键方面是它对单电子（轨道）基组的依赖性，即使对于在轨道的酉变换下不变的波函数也是如此。在这项工作中，我们研究了轨道基组（根据不同策略进行离域或定域）对于表示为斯莱特行列式线性组合的波函数的作用，并给出了一些特殊情况下MI的解析表达式。本研究旨在增进对化学键特征（考虑一些典型分子，如H、F、N和短线性多烯）与量子信息理论领域中感兴趣的性质之间关系的认识。
