  Typ výsledku
Autor celku
Název celku(Celkem 2 zázn.)
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| Uhlirova, Tereza; Zamastil, Jaroslav; Benda, Jakub. Calculation of atomic integrals between relativistic functions by means of algebraic methods. Computer Physics Communications, 2022, sv. 280, s. 108490-1–108490-15. ISSN 0010-4655. IF 4.717. [Článek v časopise] In this paper, we focus on use of the relativistic Sturmian basis set. We propose a numerically stable algorithm for the evaluation of one- and two-electron matrix elements. Thus we defeat the major impediment of a wider use of this basis set in precise atomic structure calculations. The use of the proposed method and its significance is illustrated on a series of calculations. For instance, we evaluate the so-called parity non-conserving amplitude for cesium; this is a second-order property and thus greatly depends on the accuracy of the used wave functions.
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| Uhlirova, Tereza; Zamastil, Jaroslav, Manuscript in preparation. This is a continuation of our previous paper published in Comp. Phys. Commun. in 2022. Here, we focus on the inclusion of electron correlation. We use the well-known coupled cluster (CC) method for closed shells and a combined configuration interaction-CC (CI-CC) method for one-electron open shells. We take advantage of the spherical symmetry of atoms and propose a symmetry-adapted form of the CC and CI-CC approaches; this idea significantly reduces the number of terms to be evaluated as well as the number of equations to be solved. This method is illustrated on the ionization energies of I.A elements. [Jiný výsledek] |
