How accurate are EOM-CC4 vertical excitation energies?

Abstract

We report the first investigation of the performance of EOM-CC4 -- an approximate equation-of-motion coupled-cluster model which includes iterative quadruple excitations -- for vertical excitation energies in molecular systems. By considering a set of 28 excited states in 10 small molecules for which we have computed CCSDTQP and FCI reference energies, we show that, in the case of excited states with a dominant contribution from the single excitations, CC4 yields excitation energies with sub-kJ~mol${}^{-1}$ accuracy (i.e., error below $0.01$ eV), in very close agreement with its more expensive CCSDTQ parent. Therefore, if one aims at high accuracy, CC4 stands as a highly competitive approximate method to model molecular excited states, with a significant improvement over both CC3 and CCSDT. Our results also evidence that, although the same qualitative conclusions hold, one cannot reach the same level of accuracy for transitions with a dominant contribution from the double excitations.

arXiv comment6 pages, 2 figures

References in corpus (27)

• Heat-bath Configuration Interaction: An efficient selected CI algorithm inspired by heat-bath sampling
• Semistochastic Heat-bath Configuration Interaction method: selected configuration interaction with semistochastic perturbation theory
• A Mountaineering Strategy to Excited States: Highly-Accurate Reference Energies and Benchmarks
• A deterministic alternative to the full configuration interaction quantum Monte Carlo method
• A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Medium Size Molecules
• Reference Energies for Double Excitations
• The Quest For Highly Accurate Excitation Energies: A Computational Perspective
• Quantum Package 2.0: An Open-Source Determinant-Driven Suite of Programs
• QUESTDB: a database of highly-accurate excitation energies for the electronic structure community
• The Ground State Electronic Energy of Benzene
• Excited states using semistochastic heat-bath configuration interaction
• Fast Semistochastic Heat-Bath Configuration Interaction
• Hybrid stochastic-deterministic calculation of the second-order perturbative contribution of multireference perturbation theory
• Excited States of Methylene, Polyenes, and Ozone from Heat-Bath Configuration Interaction
• Selected configuration interaction dressed by perturbation
• Adaptive multiconfigurational wave functions
• Machine Learning Configuration Interaction
• Fixed-Node Diffusion Monte Carlo potential energy curve of the fluorine molecule F2 using selected configuration interaction trial wavefunctions
• A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Exotic Molecules and Radicals
• Virtual orbital many-body expansions: A possible route towards the full configuration interaction limit
• The Shape of Full Configuration Interaction to Come
• A Mountaineering Strategy to Excited States: Highly-Accurate Oscillator Strengths and Dipole Moments of Small Molecules
• Almost exact energies for the Gaussian-2 set with the semistochastic heat-bath configuration interaction method
• Full Coupled-Cluster Reduction for Accurate Description of Strong Electron Correlation
• The performance of CIPSI on the ground state electronic energy of benzene
• Generalized Many-Body Expanded Full Configuration Interaction Theory
• Accurate many-body electronic structure near the basis set limit: application to the chromium dimer

Cited by in corpus (16)

• Accurate full configuration interaction correlation energy estimates for five- and six-membered rings
• Reference Energies for Valence Ionizations and Satellite Transitions
• A Mountaineering Strategy to Excited States: Revising Reference Values with EOM-CC4
• Reference Energies for Cyclobutadiene: Automerization and Excited States
• Reference CC3 Excitation Energies for Organic Chromophores: Benchmarking TD-DFT, BSE/$GW$ and Wave Function Methods
• Ground- and Excited-State Dipole Moments and Oscillator Strengths of Full Configuration Interaction Quality
• The QUEST Database of Highly-Accurate Excitation Energies
• Reference Vertical Excitation Energies for Transition Metal Compounds
• Quantum Equation of Motion with Orbital Optimization for Computing Molecular Properties in Near-Term Quantum Computing
• Anomalous propagators and the particle-particle channel: Bethe-Salpeter equation
• Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation
• Energy-Specific Bethe-Salpeter Equation Implementation for Efficient Optical Spectrum Calculations
• Rank-reduced equation-of-motion coupled cluster triples: an accurate and affordable way of calculating electronic excitation energies
• Rank-reduced equation-of-motion coupled cluster formalism with full inclusion of triple excitations
• LibppRPA: An Open-Source Library for Particle-Particle Random Phase Approximation
• A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Bicyclic Systems