Vibrational and electronic structure of the3d−1→4p(π,σ)−2

Abstract

Fully relativistic, self-consistent field calculations, based on the Dirac-Coulomb-Gaunt Hamiltonian, were performed on the ground state of HBr, the Br 3d -ionized HBr ϩ , and the 4p(,) Ϫ2 states of HBr 2ϩ . Correlation in the ground and valence-excited states and partially in the Br 3d ionized states was described using a configuration-interaction ͑CI͒ method. Calculated ionization energies and bond lengths were found to be in good agreement with recent experimental results. The distortion in the vibrational bands of the 3d Ϫ1 →4p Ϫ2 Auger transitions due to lifetime vibrational interference was verified through ab initio calculations. Bands due to the transitions to bound and continuum vibrational states of the same electronic state were reproduced by calculations and compared with experimentally determined profiles. The nonadiabatic effects in the spin-orbit-induced avoided level crossing were investigated using adiabatic and diabatic electronic basis sets.

Selectivity of the Br 3d−1 Auger decays in HBr

“…[48] for the M 4,5 N 1,2,3 N 1,2,3 Auger decays of the Bromine and the Krypton atoms in atomic units. (20,11) 0.003380 0.005126 R 2 (21,01) −0.040152 −0.035761 R 1 (21,10) −0.034111 −0.029106 R 2 (22,00) −0.091011 −0.083604 R 1 (22,11) −0.061545 −0.052556 R 3 (22,11) −0.052822 −0.048486 R 2 (23,01) −0.113179 −0.113431 R 3 (23,10) −0.081707 −0.084244 R 3 (24,11) 0.040778 0.043253 described above are collected in Table IV where the orbitals are represented as usual by their angular momentum quantum numbers, l.…”

“…Finally, Alagia et al [21] observed these vibrational states by measuring two threshold electrons in coincidence. The corresponding potential curves were calculated by Matila et al [22]. The molecular-field splitting of the Br 3d −1 core holes was resolved in photoelectron spectra [23][24][25] which also give access to their lifetime broadening [26].…”

Normal Auger spectra of Br in alkali bromide molecules

“…There is also a similar trend in the MF separations of the core-hole states ͑see Table I͒-the splittings between the three 3d 5/2 and two 3d 3/2 multiplets decrease for the heavier alkali bromides. 11 Analogously, spin-orbit interaction calculations gave us the additional splittings of 0.04 eV in 3 ⌺ Ϫ sates, and large splttings of 0.2 eV in 3 ⌸ states in the ionic XBr compounds. The calculated energies are smaller than the experimental values by 0.2 eV.…”

“…Cederbaum et al computed the KL 2,3 L 2,3 AES of the HF, LiF, and KF molecules. 10,11 Their results were much more precise as compared to Wannberg's initial assignment. 10,11 Their results were much more precise as compared to Wannberg's initial assignment.…”

“…20 For the Br 3d Ϫ1 core-hole states, the spin-orbit splitting 1.14 eV was obtained using the Cowan's code. 11,22 The core-hole and the double-hole ͑Auger final͒ state energies were calculated by means of the restricted active space ͑RAS͒ configuration interaction ͑Cl͒ method, implemented in Dalton, 20 in which the Br 4p(,) and Br 4s were in RAS2, all virtual orbitals were in RAS3 and RAS1 was kept empty. The splittings have been obtained to be in agreement with fully relativistic calculations in the case of HBr.…”