PSEUDOPOTENTIAL STUDIES ON THE ELECTRONIC STRUCTURE OF LANTHANUM MONOHALIDES LaF, LaCl, LaBr, AND LaI

Abstract

Relativistic energy-consistent small-core lanthanide pseudopotentials of the Stuttgart–Köln variety and corresponding valence basis sets have been used for the investigation of the ground state (1Σ+) lanthanum monohalides LaF , LaCl , LaBr , and LaI . The molecular constants were derived from coupled-cluster calculations, taking into account corrections for atomic spin-orbit splitting as well as basis set superposition errors. With the exception of the binding energies for LaI the theoretical values for LaF (Re = 2.034 Å, De = 6.73 eV , ωe = 574 cm -1), LaCl (Re = 2.517 Å, De = 5.11 eV , ωe = 339 cm -1), LaBr (Re = 2.664 Å, De = 4.47 eV , ωe = 236 cm -1), and LaI (Re = 2.891 Å, De = 3.65 eV , ωe = 186 cm -1) show good agreement with the experimental data. The calculated binding energy (3.65 eV) for LaI is in-between the two conflicting estimated experimental data (2.97 eV, 4.29 eV).