New Strategies in Modeling Electronic Structures and Properties with Applications to Actinides

Abstract

This chapter discusses contemporary quantum chemical methods and provides general insights into modern electronic structure theory with a focus on heavy-element-containing compounds. We first give a short overview of relativistic Hamiltonians that are frequently applied to account for relativistic effects. Then, we scrutinize various quantum chemistry methods that approximate the $N$-electron wave function. In this respect, we will review the most popular single- and multi-reference approaches that have been developed to model the multi-reference nature of heavy element compounds and their ground- and excited-state electronic structures. Specifically, we introduce various flavors of post-Hartree--Fock methods and optimization schemes like the complete active space self-consistent field method, the configuration interaction approach, the Fock-space coupled cluster model, the pair-coupled cluster doubles ansatz, also known as the antisymmetric product of 1 reference orbital geminal, and the density matrix renormalization group algorithm. Furthermore, we will illustrate how concepts of quantum information theory provide us with a qualitative understanding of complex electronic structures using the picture of interacting orbitals. While modern quantum chemistry facilitates a quantitative description of atoms and molecules as well as their properties, concepts of quantum information theory offer new strategies for a qualitative interpretation that can shed new light onto the chemistry of complex molecular compounds.

arXiv comment43 pages, 3 figures, Version of Record

References in corpus (25)

• The density-matrix renormalization group
• Automated Selection of Active Orbital Spaces
• The density matrix renormalization group for ab initio quantum chemistry
• Tensor product methods and entanglement optimization for ab initio quantum chemistry
• Measuring orbital interaction using quantum information theory
• Quantum information analysis of electronic states at different molecular structures
• Entanglement Measures for Single- and Multi-Reference Correlation Effects
• Efficient description of strongly correlated electrons with mean-field cost
• Orbital entanglement in bond-formation processes
• Orbital entanglement in quantum chemistry
• A flexible multi-reference perturbation theory by minimizing the Hylleraas functional with matrix product states
• Projected seniority-two orbital optimization of the Antisymmetric Product of one-reference orbital Geminal
• Linearized Coupled Cluster Correction on the Antisymmetric Product of 1 reference orbital Geminals
• Targeting excited states in all-trans polyenes with electron-pair states
• A nonorthogonal state-interaction approach for matrix product state wave functions
• The correlation theory of the chemical bond
• Quantum Entanglement in Carbon-Carbon, Carbon-Phosphorus and Silicon-Silicon Bonds
• Unravelling the quantum-entanglement effect of noble gas coordination on the spin ground state of CUO
• A quantum informational approach for dissecting chemical reactions
• Entanglement patterns and generalized correlation functions in quantum many body systems
• On the Multi-Reference Nature of Plutonium Oxides: PuO${}_2^{2+}$, PuO${}_2$, PuO${}_3$ and PuO${}_2$(OH)${}_2$
• Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals
• Combinations of coupled cluster, density functionals, and the random phase approximation for describing static and dynamic correlation, and van der Waals interactions
• Elucidating cation--cation interactions in neptunyl dications using multireference ab initio theory
• Electron correlation effects of the ThO and ThS molecules in the spinor basis. A relativistic coupled cluster study of ground and excited states properties

Cited by in corpus (3)

• Pythonic Black-box Electronic Structure Tool (PyBEST). An open-source Python platform for electronic structure calculations at the interface between chemistry and physics
• Benchmarking the accuracy of seniority-zero wavefunction methods for non-covalent interactions
• Modeling the electronic structures of the ground and excited states of the ytterbium atom and the ytterbium dimer: A modern quantum chemistry perspective