Electronic states and spin-orbit splitting of lanthanum dimer

Yang Liu, Lu Wu, Chang Hua Zhang, Serge A. Krasnokutski, Dong Sheng Yang

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Lanthanum dimer (La2) was studied by mass-analyzed threshold ionization (MATI) spectroscopy and a series of multi-configuration ab initio calculations. The MATI spectrum exhibits three band systems originating from ionization of the neutral ground electronic state, and each system shows vibrational frequencies of the neutral molecule and singly charged cation. The three ionization processes are La2+ (a2Σ g+) ← La2 (X1Σ g+), La2+ (b2Π 3/2, u) ← La2 (X1Σg +), and La2+ (b2Π 1/2, u) La2 (X1g+), with the ionization energies of 39 046, 40 314, and 40 864cm-1, respectively. The vibrational frequency of the X1g + state is 207cm-1, and those of the a2Σ g+, b2Π3/2, u and b 2Π1/2, u are 235.7, 242.2, and 240cm-1. While X1Σg+ is the ground state of the neutral molecule, a2Σg+ and b 2Πu are calculated to be the excited states of the cation. The spin-orbit splitting in the b2Πu ion is 550cm-1. An X4Σg- state of La2+ was predicted by theory, but not observed by the experiment. The determination of a singlet ground state of La2 shows that lanthanum behaves differently from scandium and yttrium.

Original languageEnglish
Article number034309
JournalJournal of Chemical Physics
Issue number3
StatePublished - Jul 21 2011

Bibliographical note

Funding Information:
We are grateful for the financial support from the National Science Foundation Division of Chemistry. We also acknowledge additional support from donors of the Petroleum Research Fund of the American Chemical Society and Kentucky Science and Engineering Foundation.

ASJC Scopus subject areas

  • Physics and Astronomy (all)
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Electronic states and spin-orbit splitting of lanthanum dimer'. Together they form a unique fingerprint.

Cite this