Entanglement Measures for Single- and Multi-Reference Correlation Effects

Abstract

Electron correlation effects are essential for an accurate ab initio description of molecules. A quantitative a priori knowledge of the single- or multi-reference nature of electronic structures as well as of the dominant contributions to the correlation energy can facilitate the decision regarding the optimum quantum chemical method of choice. We propose concepts from quantum information theory as orbital entanglement measures that allow us to evaluate the single- and multi-reference character of any molecular structure in a given orbital basis set. By studying these measures we can detect possible artifacts of small active spaces.

14 pages, 4 figures

References in corpus (3)

• The radical character of the acenes: A density matrix renormalization group study
• Accurate ab initio spin densities
• Construction of CASCI-type wave functions for very large active spaces

Cited by in corpus (11)

• The density matrix renormalization group for ab initio quantum chemistry
• Multi-reference perturbation theory with Cholesky decomposition for the density matrix renormalization group
• Separation of Dynamic and Nondynamic Correlation
• Projected seniority-two orbital optimization of the Antisymmetric Product of one-reference orbital Geminal
• DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)
• Investigation of metal-insulator like transition through the ab initio density matrix renormalization group approach
• Analysis of two-orbital correlations in wavefunctions restricted to electron-pair states
• Self-Consistent Embedding of Density-Matrix Renormalization Group Wavefunctions in a Density Functional Environment
• A quantum informational approach for dissecting chemical reactions
• Stretching and breaking of chemical bonds, correlation of electrons, and radical properties of covalent species
• Spin entanglement in atoms and molecules