dorsal/arxiv
View SchemaNon-Hermitian Rayleigh-Schroedinger Perturbation Theory
| Authors | Christian Buth, Robin Santra, Lorenz S. Cederbaum |
|---|---|
| Categories | |
| ArXiv ID | physics/0401081 |
| URL | https://arxiv.org/abs/physics/0401081 |
| DOI | 10.1103/PhysRevA.69.032505 |
| Journal | Phys. Rev. A 69, 032505 (2004) [9 pages] |
| License | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
Abstract
We devise a non-Hermitian Rayleigh-Schroedinger perturbation theory for the single- and the multireference case to tackle both the many-body problem and the decay problem encountered, for example, in the study of electronic resonances in molecules. A complex absorbing potential (CAP) is employed to facilitate a treatment of resonance states that is similar to the well-established bound-state techniques. For the perturbative approach, the full CAP-Schroedinger Hamiltonian, in suitable representation, is partitioned according to the Epstein-Nesbet scheme. The equations we derive in the framework of the single-reference perturbation theory turn out to be identical to those obtained by a time-dependent treatment in Wigner-Weisskopf theory. The multireference perturbation theory is studied for a model problem and is shown to be an efficient and accurate method. Algorithmic aspects of the integration of the perturbation theories into existing ab initio programs are discussed, and the simplicity of their implementation is elucidated.
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"abstract": "We devise a non-Hermitian Rayleigh-Schroedinger perturbation theory for the\nsingle- and the multireference case to tackle both the many-body problem and\nthe decay problem encountered, for example, in the study of electronic\nresonances in molecules. A complex absorbing potential (CAP) is employed to\nfacilitate a treatment of resonance states that is similar to the\nwell-established bound-state techniques. For the perturbative approach, the\nfull CAP-Schroedinger Hamiltonian, in suitable representation, is partitioned\naccording to the Epstein-Nesbet scheme. The equations we derive in the\nframework of the single-reference perturbation theory turn out to be identical\nto those obtained by a time-dependent treatment in Wigner-Weisskopf theory. The\nmultireference perturbation theory is studied for a model problem and is shown\nto be an efficient and accurate method. Algorithmic aspects of the integration\nof the perturbation theories into existing ab initio programs are discussed,\nand the simplicity of their implementation is elucidated.",
"arxiv_id": "physics/0401081",
"authors": [
"Christian Buth",
"Robin Santra",
"Lorenz S. Cederbaum"
],
"categories": [
"physics.chem-ph",
"physics.atom-ph"
],
"doi": "10.1103/PhysRevA.69.032505",
"journal_ref": "Phys. Rev. A 69, 032505 (2004) [9 pages]",
"license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
"title": "Non-Hermitian Rayleigh-Schroedinger Perturbation Theory",
"url": "https://arxiv.org/abs/physics/0401081"
},
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