title: Complex absorbing potentials within EOM-CC family of methods: theory, implementation, and benchmarks.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Zuev
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Thomas-C
authors.initials: TC
authors.lastname: Jagau
authors.affiliation: Department of Chemistry, Boston University, Boston, Massachusetts 02215-2521, USA.
authors.forename: Ksenia B
authors.initials: KB
authors.lastname: Bravaya
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Epifanovsky
authors.affiliation: Q-Chem, Inc., 6601 Owens Drive, Suite 105 Pleasanton, California 94588, USA.
authors.forename: Yihan
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Sundstrom
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Head-Gordon
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Anna I
authors.initials: AI
authors.lastname: Krylov
mesh_terms: D000327:Adsorption; D004583:Electrons; D008962:Models, Theoretical; D011789:Quantum Theory