## The generalized sturmian method for calculating spectra of atoms and ions

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**The generalized sturmian method for calculating spectra of atoms and ions.** / Avery, James Emil; Avery, John Scales.

Research output: Contribution to journal › Journal article › Research › peer-review

#### Harvard

*Journal of Mathematical Chemistry*, vol. 33, pp. 145-162. https://doi.org/10.1023/A:1023204016217

#### APA

*Journal of Mathematical Chemistry*,

*33*, 145-162. https://doi.org/10.1023/A:1023204016217

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#### RIS

TY - JOUR

T1 - The generalized sturmian method for calculating spectra of atoms and ions

AU - Avery, James Emil

AU - Avery, John Scales

N1 - Paper id:: 10.1023/A:1023204016217

PY - 2003

Y1 - 2003

N2 - The properties of generalized Sturmian basis sets are reviewed, and functions of this type are used to perform direct configuration interaction calculations on the spectra of atoms and ions. Singlet excited states calculated in this way show good agreement with experimentally measured spectra. When the generalized Sturmian method is applied to atoms, the configurations are constructed from hydrogenlike atomic orbitals with an effective charge which is characteristic of the configuration. Thus, orthonormality between the orbitals of different configurations cannot be assumed, and the generalized Slater–Condon rules must be used. This aspect of the problem is discussed in detail. Finally spectra are calculated in the presence of a strong external electric field. In addition to the expected Stark effect, the calculated spectra exhibit anomalous states. These are shown to be states where one of the electrons is primarily outside the atom or ion, with only a small amplitude inside.

AB - The properties of generalized Sturmian basis sets are reviewed, and functions of this type are used to perform direct configuration interaction calculations on the spectra of atoms and ions. Singlet excited states calculated in this way show good agreement with experimentally measured spectra. When the generalized Sturmian method is applied to atoms, the configurations are constructed from hydrogenlike atomic orbitals with an effective charge which is characteristic of the configuration. Thus, orthonormality between the orbitals of different configurations cannot be assumed, and the generalized Slater–Condon rules must be used. This aspect of the problem is discussed in detail. Finally spectra are calculated in the presence of a strong external electric field. In addition to the expected Stark effect, the calculated spectra exhibit anomalous states. These are shown to be states where one of the electrons is primarily outside the atom or ion, with only a small amplitude inside.

KW - Faculty of Science

KW - Sturm-baser

KW - den generalisede Sturm-metode

KW - atomspektre

KW - kvantekemi

KW - Sturmian bases

KW - generalized Sturmian method

KW - atomic spectra

KW - quantum chemistry

U2 - 10.1023/A:1023204016217

DO - 10.1023/A:1023204016217

M3 - Journal article

VL - 33

SP - 145

EP - 162

JO - Journal of Mathematical Chemistry

JF - Journal of Mathematical Chemistry

SN - 0259-9791

ER -

ID: 124785