Measuring Multi-Configurational Character by Orbital Entanglement

Abstract

One of the most critical tasks at the very beginning of a quantum chemical investigation is the choice of either a multi- or single-configurational method. Naturally, many proposals exist to define a suitable diagnostic of the multi-configurational character for various types of wave functions in order to assist this crucial decision. Here, we present a new orbital-entanglement based multi-configurational diagnostic termed $Z_{s(1)}$. The correspondence of orbital entanglement and static (or nondynamic) electron correlation permits the definition of such a diagnostic. We chose our diagnostic to meet important requirements such as well-defined limits for pure single-configurational and multi-configurational wave functions. The $Z_{s(1)}$ diagnostic can be evaluated from a partially converged, but qualitatively correct, and therefore inexpensive density matrix renormalization group wave function as in our recently presented automated active orbital selection protocol. Its robustness and the fact that it can be evaluated at low cost make this diagnostic a practical tool for routine applications.

8 pages, 2 figure, 3 tables

References in corpus (15)

• The density-matrix renormalization group in the age of matrix product states
• W4 theory for computational thermochemistry: in pursuit of confident sub-kJ/mol predictions
• The radical character of the acenes: A density matrix renormalization group study
• Automated Selection of Active Orbital Spaces
• The density matrix renormalization group for ab initio quantum chemistry
• Spin in Density-Functional Theory
• Multireference Correlation in Long Molecules with the Quadratic Scaling Density Matrix Renormalization Group
• Entanglement Measures for Single- and Multi-Reference Correlation Effects
• The Delicate Balance of Static and Dynamic Electron Correlation
• Spin-adapted Matrix Product States and Operators
• Matrix Product State applications for the ALPS project
• Dynamical Mean-Field Theory for Quantum Chemistry
• Construction of CASCI-type wave functions for very large active spaces
• Analysis of two-orbital correlations in wavefunctions restricted to electron-pair states
• Applying Monte Carlo configuration interaction to transition metal dimers: exploring the balance between static and dynamic correlation

Cited by in corpus (25)

• Elucidating Reaction Mechanisms on Quantum Computers
• Machine learning for electronically excited states of molecules
• The Density Matrix Renormalization Group in Chemistry and Molecular Physics: Recent Developments and New Challenges
• Drug design on quantum computers
• Large-scale quantum-dynamics with matrix product states
• autoCAS: a program for fully automated multi-configurational calculations
• Error-Controlled Exploration of Chemical Reaction Networks with Gaussian Processes
• Automated Identification of Relevant Frontier Orbitals for Chemical Compounds and Processes
• Calculation of Ligand Dissociation Energies in Large Transition-Metal Complexes
• Concept of orbital entanglement and correlation in quantum chemistry
• Measuring Electron Correlation. The Impact of Symmetry and Orbital Transformations
• Tailored Coupled Cluster Theory in Varying Correlation Regimes
• Efficient reconstruction of CASCI-type wave functions for a DMRG state using quantum information theory and genetic algorithm
• Electron Dynamics with the Time-Dependent Density Matrix Renormalization Group
• Reduced-density-matrix-based ab initio cavity quantum electrodynamics
• Quantum correlations in molecules: from quantum resourcing to chemical bonding
• High-throughput ab initio reaction mechanism exploration in the cloud with automated multi-reference validation
• What Can Quantum Information Theory Offer to Quantum Chemistry?
• Unveiling Intrinsic Many-Body Complexity by Compressing Single-Body Triviality
• High ground state overlap via quantum embedding methods
• Solving an Industrially Relevant Quantum Chemistry Problem on Quantum Hardware
• Orbital Entanglement and The Double $d$-Shell Effect in Binary Transition Metal Molecules
• Heron: Visualizing and Controlling Chemical Reaction Explorations and Networks
• Measuring Correlation and Entanglement between Molecular Orbitals on a Trapped-Ion Quantum Computer
• Shannon and Rényi entropies of molecular densities: insights into extensivity and the incomplete description of electron correlation