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Updated: Mar 31, 2026

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
Anion Photoelectron Spectroscopy and CASSCF/CASPT2/RASSI Study of Lan(-) (n = 1, 3-7)
A S Ivanov1, X Zhang2, H Wang2
1Department of Chemistry and Biochemistry, Utah State University , 0300 Old Main Hill, Logan, Utah 84322-0300, United States.
Abstract:
We present a combined experimental and theoretical study of small lanthanum clusters. The experimental photoelectron spectra of Lan(-) (n = 1, 3-7) were obtained using negative ion photoelectron spectroscopy. Electron affinities for these clusters were found to be in a range of 0.49 eV (La) to 1.5 eV (La7). Our computational tour de force in exploring the electronic structure and its consequences for the lanthanum atom and its anion as well as for lanthanum trimer and its anion shows the multiconfigurational method and large basis set with spin-orbit corrections: CASSCF/CASPT2/RASSI/ANO-RCC-L level of theory is needed to reproduce experimental accuracy. The most stable structure for La3(-) was established to be an equilateral triangle ((1)A1'). Chemical bonding analysis of the La3(-) global minimum reveals that this is the first experimentally observed species with d-AO double σ and π aromaticity.
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