Calculating the Lifetimes of Metastable States with Complex Density Functional Theory

Zhou, Yongxi; Ernzerhof, Matthias

doi:10.1021/jz3006805

Cited by 47 publications

(57 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…24 Preliminary benchmarks illustrated that this approach results in a computationally more robust scheme in which the dependence on the onset of the CAP is significantly reduced compared to the straightforward application of a CAP along with the original energybased criterion for finding the optimal η, as was done in most CAP applications. [25][26][27] We note that Moiseyev et al 28,29 also observed a linear energy dependence on η beyond some critical value of η and proposed the use of Padé approximants to extrapolate the energy of the stabilized resonance to the zero η limit. If the energy depends strictly linearly on η, their approach yields results identical to our first-order correction.…”

Section: Introductionmentioning

confidence: 78%

Complex absorbing potentials within EOM-CC family of methods: Theory, implementation, and benchmarks

Zuev

Jagau

Bravaya

et al. 2014

The Journal of Chemical Physics

138

216

View full text Add to dashboard Cite

A production-level implementation of equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) for electron attachment and excitation energies augmented by a complex absorbing potential (CAP) is presented. The new method enables the treatment of metastable states within the EOM-CC formalism in a similar manner as bound states. The numeric performance of the method and the sensitivity of resonance positions and lifetimes to the CAP parameters and the choice of one-electron basis set are investigated. A protocol for studying molecular shape resonances based on the use of standard basis sets and a universal criterion for choosing the CAP parameters are presented. Our results for a variety of π(*) shape resonances of small to medium-size molecules demonstrate that CAP-augmented EOM-CCSD is competitive relative to other theoretical approaches for the treatment of resonances and is often able to reproduce experimental results.

show abstract

Section: Introductionmentioning

confidence: 78%

Complex absorbing potentials within EOM-CC family of methods: Theory, implementation, and benchmarks

Zuev

Jagau

Bravaya

et al. 2014

The Journal of Chemical Physics

138

216

View full text Add to dashboard Cite

show abstract

“…In Table III we have listed theoretical results obtained by other workers. Our current results with our best basis set (14s14p5d) are quite far from complex CI [39] and density functional theory (DFT) combined with a CAP [42] calculations. We note that the CI calculations did not include any effect of quadruple excitations.…”

Section: Resultsmentioning

confidence: 68%

Electron-atom resonances: The complex-scaled multiconfigurational spin-tensor electron propagator method for the2PBe−shape resonance problem

2015

View full text Add to dashboard Cite

We propose and develop the complex scaled multiconfigurational spin-tensor electron propagator (CMCSTEP) technique for theoretical determination of resonance parameters with electronatom/molecule systems including open-shell and highly correlated atoms and molecules. The multiconfigurational spin-tensor electron propagator method (MCSTEP) developed and implemented by Yeager his coworkers in real space gives very accurate and reliable ionization potentials and attachment energies. The CMCSTEP method uses a complex scaled multiconfigurational selfconsistent field (CMCSCF) state as an initial state along with a dilated Hamiltonian where all of the electronic coordinates are scaled by a complex factor. CMCSCF was developed and applied successfully to resonance problems earlier. We apply the CMCSTEP method to get 2 P Be − shape resonance parameters using 14s11p5d, 14s14p2d, and 14s14p5d basis sets with a 2s2p3d CAS. The obtained value of the resonance parameters are compared to previous results. This is the first time CMCSTEP has been developed and used for a resonance problem. It will be among the most accurate and reliable techniques. Vertical ionization potentials and attachment energies in real space are typically within ±0.2 eV or better of excellent experiments and full configuration interaction calculations with a good basis set. We expect the same sort of agreement in complex space.

show abstract

“…19,42 Complex scaling and CAP techniques have been applied to several ab initio methods. Complex-scaled and CAP Hartree-Fock (HF) 43,44 and density functional theory (DFT) 45 methods have been introduced; these approaches are only applicable for metastable ground electronic states. Complexscaled configuration-interaction (CI) 43 and multiconfigurational self-consistent field (MCSCF) 44 were successfully used to study resonances in atoms and small molecules, e.g., He, H 2 , Be − .…”

Section: Introductionmentioning

confidence: 99%

Complex-scaled equation-of-motion coupled-cluster method with single and double substitutions for autoionizing excited states: Theory, implementation, and examples

Bravaya

Zuev

Epifanovsky

et al. 2013

The Journal of Chemical Physics

View full text Add to dashboard Cite

Theory and implementation of complex-scaled variant of equation-of-motion coupled-cluster method for excitation energies with single and double substitutions (EOM-EE-CCSD) is presented. The complex-scaling formalism extends the EOM-EE-CCSD model to resonance states, i.e., excited states that are metastable with respect to electron ejection. The method is applied to Feshbach resonances in atomic systems (He, H(-), and Be). The dependence of the results on one-electron basis set is quantified and analyzed. Energy decomposition and wave function analysis reveal that the origin of the dependence is in electron correlation, which is essential for the lifetime of Feshbach resonances. It is found that one-electron basis should be sufficiently flexible to describe radial and angular electron correlation in a balanced fashion and at different values of the scaling parameter, θ. Standard basis sets that are optimized for not-complex-scaled calculations (θ = 0) are not sufficiently flexible to describe the θ-dependence of the wave functions even when heavily augmented by additional sets.

show abstract

Calculating the Lifetimes of Metastable States with Complex Density Functional Theory

Cited by 47 publications

References 37 publications

Complex absorbing potentials within EOM-CC family of methods: Theory, implementation, and benchmarks

Complex absorbing potentials within EOM-CC family of methods: Theory, implementation, and benchmarks

Electron-atom resonances: The complex-scaled multiconfigurational spin-tensor electron propagator method for the2PBe−shape resonance problem

Complex-scaled equation-of-motion coupled-cluster method with single and double substitutions for autoionizing excited states: Theory, implementation, and examples

Contact Info

Product

Resources

About