Cossard Alessandro, Casassa Silvia, Gatti Carlo, Desmarais Jacques K, Erba Alessandro
Dipartimento di Chimica, Università di Torino, Via Giuria 5, 10125 Torino, Italy.
CNR-SCITEC, Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Via C. Golgi 19, 20133 Milano, Italy.
Molecules. 2021 Jul 12;26(14):4227. doi: 10.3390/molecules26144227.
The chemistry of -electrons in lanthanide and actinide materials is yet to be fully rationalized. Quantum-mechanical simulations can provide useful complementary insight to that obtained from experiments. The quantum theory of atoms in molecules and crystals (QTAIMAC), through thorough topological analysis of the electron density (often complemented by that of its Laplacian) constitutes a general and robust theoretical framework to analyze chemical bonding features from a computed wave function. Here, we present the extension of the Topond module (previously limited to work in terms of -, - and -type basis functions only) of the Crystal program to - and -type basis functions within the linear combination of atomic orbitals (LCAO) approach. This allows for an effective QTAIMAC analysis of chemical bonding of lanthanide and actinide materials. The new implemented algorithms are applied to the analysis of the spatial distribution of the electron density and its Laplacian of the cesium uranyl chloride, Cs2UO2Cl4, crystal. Discrepancies between the present theoretical description of chemical bonding and that obtained from a previously reconstructed electron density by experimental X-ray diffraction are illustrated and discussed.
镧系和锕系材料中π电子的化学性质尚未得到充分合理的解释。量子力学模拟可以为从实验中获得的结果提供有用的补充见解。分子和晶体中的原子量子理论（QTAIMAC）通过对电子密度进行全面的拓扑分析（通常辅以其拉普拉斯算子的分析），构成了一个通用且强大的理论框架，用于从计算得到的波函数分析化学键特征。在此，我们展示了Crystal程序的Topond模块（以前仅限于仅使用π、σ和ζ型基函数）在线性组合原子轨道（LCAO）方法内对γ和δ型基函数的扩展。这使得对镧系和锕系材料的化学键进行有效的QTAIMAC分析成为可能。新实现的算法被应用于分析氯化铯酰铀（Cs2UO2Cl4）晶体的电子密度及其拉普拉斯算子的空间分布。本文对化学键的理论描述与先前通过实验X射线衍射重建的电子密度所得到的描述之间的差异进行了说明和讨论。
