Intermediate state representation approach to physical properties of molecular electron-detached states. I. Theory and implementation

Abstract

The third-order non-Dyson algebraic-diagrammatic construction approach to the electron propagator [IP-ADC(3)] is extended using the intermediate state representation (ISR) formalism, allowing the wave functions and properties of molecular states with detached electron to be studied. The second-order ISR equations [ISR(2)] for the one-particle (transition) density matrix have been derived and implemented in the Q-CHEM program. The approach is completely general and enables evaluation of arbitrary one-particle operators and interpretation of electron detachment processes in terms of density-based quantities. The IP-ADC(3)/ISR(2) equations were implemented for Ŝz-adapted intermediate states, allowing open-shell molecules to be studied using unrestricted Hartree-Fock references. As a first test for computations of ground state properties, dipole moments of various closed- and open-shell molecules have been computed by means of electron detachment from the corresponding anions. The results are in good agreement with experimental data. The potential of IP-ADC(3)/ISR(2) for the interpretation of photoelectron spectra is demonstrated for the galvinoxyl free radical.

Valence shell photoelectron angular distributions and vibrationally resolved spectra of imidazole: A combined experimental–theoretical study

“…[19][20][21][22] A theoretical ionization spectrum of the complete valence shell was generated using the ionization energies, and the associated relative spectral intensities, obtained with the third-order algebraic-diagrammatic construction scheme [ADC (3)] for the one-particle Green's function. 11,[23][24][25][26][27][28][29] The ADC(3) results are applicable in regions of the spectrum where the single-electron picture of ionization breaks down, 30 and are essential in the assignment of the broad photoelectron bands observed in the inner valence region of imidazole.…”

“…[IP-ADC(3)], [23][24][25][26] the third-order Dyson ADC method [ADC(3)], 11,[27][28][29] the equation-of-motion coupled-cluster (CC) theory for ionization potentials at the level of singles and doubles model (EOM-IP-CCSD), [14][15][16][17][18] and the CC3 method [19][20][21][22] in combination with the continuum orbital approach. 49 A cc-pVTZ basis set 50,51 was used in all cases (with the exception, discussed below, of the Dyson ADC(3) calculations) and the K-shell orbitals were kept frozen.…”

“…Both methods provide an equivalent third-order description of the ionization spectrum. Whereas IP-ADC(3) is, in general, computationally very efficient, its recent implementation 25,26 still lacks a block-Lanczos diagonalization procedure. Such a procedure is crucial for the generation of the spectral envelope at energies higher than those of the outer valence region where the single electron This is the author's peer reviewed, accepted manuscript.…”

Efficient implementation of the single-reference algebraic diagrammatic construction theory for charged excitations: Applications to the TEMPO radical and DNA base pairs

“…The development of accurate yet efficient computational methods for charged electronic states is an ongoing challenge and is an active area of research. [24][25][26][27][28][29] An attractive alternative to traditional coupled cluster theory for simulating charged electronic states is algebraic diagrammatic construction (ADC) theory [30][31][32][33][34][35] that offers an efficient approach for calculating excitation energies and transition intensities from poles and residues of a many-body propagator approximated in a time-independent perturbation series. Since its formulation in 1982, single-reference ADC theory has been applied to a wide range of problems in chemistry and a) Electronic mail: sokolov.8@osu.edu spectroscopy, including simulating UV/Vis 30,36,37 and Xray absorption, 38,39 photoelectron, [27][28][29]31,[40][41][42][43][44] and twophoton absorption spectra.…”

“…[24][25][26][27][28][29] An attractive alternative to traditional coupled cluster theory for simulating charged electronic states is algebraic diagrammatic construction (ADC) theory [30][31][32][33][34][35] that offers an efficient approach for calculating excitation energies and transition intensities from poles and residues of a many-body propagator approximated in a time-independent perturbation series. Since its formulation in 1982, single-reference ADC theory has been applied to a wide range of problems in chemistry and a) Electronic mail: sokolov.8@osu.edu spectroscopy, including simulating UV/Vis 30,36,37 and Xray absorption, 38,39 photoelectron, [27][28][29]31,[40][41][42][43][44] and twophoton absorption spectra. 45 The ADC methods for charged excitations (EA/IP), first proposed in 1983, were based on the Dyson framework that involves perturbative self-energy expansion of the Dyson equation and couples the EA and IP components of the one-electron propagator.…”