The (1)3Π Electronic State of LaF

Theoretical electronic structure of the lowest-lying states of the LaF molecule

“…Experimental spectroscopic constants came from the analysis of laser induced fluorescence spectra 6 and of the thermal emission spectrum of LaF recorded with a Fourier transform spectrometer. [2][3][4] Up to now to the best of our knowledge they are known for the states X 1 ⌺ ϩ , (2) 1 ⌺ ϩ , (1) 3 ⌬ 1,2,3 , (1) 1 ⌬, (1) 3 ⌸ 0,1,2 , (1) 1 ⌸, and (1) 3 ⌽ 2,3,4 . Values predicted for the adiabatic transition energies T e are smaller by an average amount of ϳ60 cm Ϫ1 from CI calculations than they are when considering Davidson correction.…”

Electronic Structure of LaF+ and LaF from Frozen-Core Four-Component Relativistic Multiconfigurational Quasidegenerate Perturbation Theory

“…The basis set for the respective calculations of C1-C4 are rather large. For example, the set for C4 is La[1*6/1*5+ (11)…”

“…For example, the set for C4 is La[1*6/1*5+(11)/1*7/1*8/(1)] + F[21/422/(1)], where a slash separates the symmetries s, p, d, f, and g symmetries, 1*n implies that n primitive Gaussian type functions (pGTFs) are used, and a 2 and 4 indicate that the contracted GTFs (cGTF) are spanned with 2 and 4 primitives, respectively. The (11) and (1) for La are two p-type polarization functions 18 and one g-type polarization function, whereas (1) for F is a single d-type polarization function. 18 The total number of molecular spinors generated is 145.…”

“…Schall, Linton, and Field identified the ground state as (6s) 2 1 ∑. Since then, there have been many experimental studies of the excited states. − (A review of spectroscopic properties of rare earths is given in ref .) Only three theoretical works have been published for LaF, however.…”

Note

“…Extensive rovibrational analyses of the spectra allowed the (1) 3 , (1) 1 , and [11.7] 3 states to be characterized for the first time and the knowledge of the X 1 + , (1) 3 , and (2) 1 + states to be greatly improved (2)(3)(4). The absolute positions in energy of the triplet-state manifolds could be precisely fixed from the observation of the (1) 3 1 → X 1 + (0-0) transition (4). Also, two weak bands with P, Q, and R structures in the 11 500 cm −1 region separated by about 36 cm −1 , were found to correspond to transitions toward the (1) 3 1 (v = 0) level.…”