Competition between Jahn-Teller effect and spin-orbit coupling in Td Au20±γ, γ=1,2,3
Facultad de Ciencias, Universidad Nacional Autónoma de México, Apdo. Post. 70-646, 04510 México D.F., Mexico
Corresponding author: a email@example.com
Revised: 27 November 2008
Published online: 29 January 2009
In this work we explored the competition between spin-orbit and Jahn-Teller effects as decisive influences in the ground states of the Td Au20±γ (γ=1,2,3). All our electronic calculations were based in the relativistic density functional theory in the zeroth-order regular approximation (ZORA) to the Dirac equation. Calculations were done in both versions of ZORA: scalar relativistic and full-relativistic including the spin-orbit interaction. We concluded that for the Au20-3 ion is necessary to use a full-relativistic theory in order to predict a symmetry-lowering from tetrahedral. We predict a trigonal C3v isomeric form for this trianion due to a Jahn-Teller distortion of its parent Td. For the rest of ions we found a tendency to conserve their pristine tetrahedral configurations. In these cases we found one of both possibilities: a quenching of the vibronic interaction by spin-orbit coupling or simply a weak Jahn-Teller effect which is not enough to distort appreciably the cluster.
PACS: 71.70.Ej – Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect / 71.15.Mb – Density functional theory, local density approximation, gradient and other corrections / 74.25.Jb – Electronic structure / 36.40.Wa – Charged clusters
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009