Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 23: Correlated Electrons: (General) Theory

TT 23.17: Vortrag

Mittwoch, 27. Februar 2008, 18:30–18:45, H 0104

Influence of electronic correlations on the ground-state properties of CeN. — •Elena Voloshina¹ and Beate Paulus² — ¹Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany — ²Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany

The electron-correlation effects on the ground-state properties of CeN were studied by ab initio quantum-chemical methods. The 4f-states of cerium were treated with 4f-in-core pseudopotential derived by M. Dolg et al. for trivalent cerium (Ce¹¹⁺-PP) [1]. The approach which was used consists in the combination of two separate steps: 1) the ground-state Hartree-Fock calculations for the crystal; 2) application of the method of increments [2] to the studied system, which allows an expansion of bulk properties using the information from quantum-chemical calculations performed for finite cluster, in connection with the size-extensive coupled-cluster method. As it can be expected, for CeN correlation play a significant role: with Hartree-Fock method only a half of the experimental cohesive energy has been covered, whereas after correlation corrections the ground-state properties were shown to be in good agreement with the experimental data found in literature. The computed ground-state properties of CeN are compared with corresponding values obtained for LaN and GdN [3].

[1] M. Dolg, P. Fulde, W. Küchle, et al. J. Chem. Phys. 94, 3011 (1991). [2] H. Stoll, Phys. Rev. B 46, 6700 (1992). [3] S. Kaldova, M. Dolg, H.-J. Flad, et al. Phys. Rev. B 57, 2127 (1998).