https://doi.org/10.1140/epjb/e2004-00266-x
Ab-initio calculation of the metal-insulator transition in sodium rings and chains and in mixed sodium-lithium systems
Max-Planck-Institut für Physik komplexer Systeme,
Nöthnitzer Straße 38, 01187 Dresden, Germany
Corresponding author: a beate@mpipks-dresden.mpg.de
Received:
29
August
2003
Revised:
29
March
2004
Published online:
31
August
2004
We study how the Mott metal-insulator transition (MIT) is influenced when we deal with electrons with different angular momenta. For lithium we found an essential effect when we include p-orbitals in the description of the Hilbert space. We apply quantum-chemical methods to sodium rings and chains in order to investigate the analogue of a MIT, and how it is influenced by periodic and open boundaries. By changing the interatomic distance we analyse the character of the many-body wavefunction and the charge gap. In the second part we mimic a behaviour found in the ionic Hubbard model, where a transition from a band to a Mott insulator occurs. For that purpose we perform calculations for mixed sodium-lithium rings. In addition, we examine the question of bond alternation for the pure sodium system and the mixed sodium-lithium system, in order to determine under which conditions a Peierls distortion occurs.
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 31.25.Qm – Electron correlation calculations for polyatomic molecules
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
