Constrained optimized potential method and second‐order correlation energy for excited states

Glushkov, V. N.; Gidopoulos, Nikitas I.

doi:10.1002/qua.21464

Cited by 15 publications

(7 citation statements)

References 67 publications

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“…Some preliminary discussions of such an assumption for singly excited states have been reported in Ref. [27]. In this work we investigate this problem for single and DCH ionized states.…”

Section: Illustrative Calculations Using a Local Parameterized Potentialmentioning

confidence: 99%

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On orthogonality constrained multiple core‐hole states and optimized effective potential method

Glushkov

Assfeld

2012

J Comput Chem

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An attempt to construct a multiple core-hole state within the optimized effective potential (OEP) methodology is presented. In contrast to the conventional Δ-self-consistent field method for hole states, the effects of removing an electron is achieved using some orthogonality constraints imposed on the orbitals so that a Slater determinant describing a hole state is constrained to be orthogonal to that of a neutral system. It is shown that single, double, and multiple core-hole states can be treated within a unified framework and can be easily implemented for atoms and molecules. For this purpose, a constrained OEP method proposed earlier for excited states (Glushkov and Levy, J. Chem. Phys. 2007, 126, 174106) is further developed to calculate single and double core ionization energies using a local effective potential expressed as a direct mapping of the external potential. The corresponding equations, determining core-hole orbitals from a one-particle Schrödinger equation with a local potential as well as correlation corrections derived from the second-order many-body perturbation theory are given. One of the advantages of the present direct mapping formulation is that the effective potential, which plays the role of the Kohn-Sham potential, has the symmetry of the external potential. Single and double core ionization potentials computed with the presented scheme were found to be in agreement with data available from experiment and other calculations. We also discuss core-hole state local potentials for the systems studied.

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“…Some preliminary discussions of such an assumption for singly excited states have been reported in Ref. [27]. In this work we investigate this problem for single and DCH ionized states.…”

Section: Illustrative Calculations Using a Local Parameterized Potentialmentioning

confidence: 99%

“…Later developments accounted for the correlation corrections derived from the second‐order many‐body perturbation theory (MBPT). [27] Application of the COEP method to double excited states of simple atoms and molecules has been done in Ref. [28].…”

Section: Introductionmentioning

confidence: 99%

On orthogonality constrained multiple core‐hole states and optimized effective potential method

Glushkov

Assfeld

2012

J Comput Chem

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“…[45][46][47] In this series of papers, the hole in the space of occupied orbitals is fixed. This is an advantage for excitation from core states since hole optimization would demand a series of calculations where all excitations above a core state had to be determined.…”

Section: Introductionmentioning

confidence: 99%

Double excitations from modified Hartree Fock subsequent minimization scheme

Tassi

Θεοφίλου

Thanos

2013

The Journal of Chemical Physics

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Doubly excited states have nowadays become important in technological applications, e.g., in increasing the efficiency of solar cells and therefore, their description using ab initio methods is a great theoretical challenge as double excitations cannot be described by linear response theories based on a single Slater determinant. In the present work we extend our recently developed Hartree-Fock (HF) approximation for calculating singly excited states [M. Tassi, I. Theophilou, and S. Thanos, Int. J. Quantum Chem. 113, 690 (2013)] in order to allow for the calculation of doubly excited states. We describe the double excitation as two holes in the subspace spanned from the occupied HF orbitals and two particles in the subspace of virtual HF orbitals. A subsequent minimization of the energy results to the determination of the spin orbitals of both the holes and the particles in the occupied and virtual subspaces, respectively. We test our method, for various atoms, H 2 and polyene molecules which are known to have excitations presenting a significant double excitation character. Importantly, our approach is computationally inexpensive.

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“…This point was confirmed, to some extent, by excited state calculations based on the COEP method proposed in [1] and later developed in Refs. [32][33][34]. It was shown, that an excited state produced by excitation of electron, for example, from orbital ϕ 0k of the ground state KS determinant Φ 0 can be presented by imposition of some orthogonality constraints on the ES orbitals.…”

Section: Outline Of Ti-dft and Its Coep Implementationmentioning

confidence: 99%

Highly Excited States from a Time Independent Density Functional Method

Glushkov

Levy

2016

Computation

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Abstract:A constrained optimized effective potential (COEP) methodology proposed earlier by us for singly low-lying excited states is extended to highly excited states having the same spatial and spin symmetry. Basic tenets of time independent density functional theory and its COEP implementation for excited states are briefly reviewed. The amended Kohn-Sham-like equations for excited state orbitals and their specific features for highly excited states are discussed. The accuracy of the method is demonstrated using exchange-only calculations for highly excited states of the He and Li atoms.

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Constrained optimized potential method and second‐order correlation energy for excited states

Cited by 15 publications

References 67 publications

On orthogonality constrained multiple core‐hole states and optimized effective potential method

On orthogonality constrained multiple core‐hole states and optimized effective potential method

Double excitations from modified Hartree Fock subsequent minimization scheme

Highly Excited States from a Time Independent Density Functional Method

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