Dynamical Auger Emission Induced by Multistate Vibronic Coupling in the Core-Excited States of theBCl3Molecule

The Auger emission following the resonant excitation of the ${\mathrm{BCl}}_3$ molecule has been investigated using monochromatized synchrotron radiation. The B $1s$ excitation to the unoccupied Anti-bonding ${4e}^{\prime }$ orbital enhances the shoulder structure in the low kinetic energy side of the photoemission from the ${2e}^{\prime }$ valence bonding orbital. Based on a series of quantum mechanical calculations, this shoulder structure is interpreted as the dynamical Auger emission which reflects the B-Cl stretching nuclear motion and appears as a result of the purely multistate vibronic coupling effect among the Jahn-Teller split B ${1s}^{-1\mathrm{}}{4e}^{\prime }{E}^{\prime }$ states and the closely lying B ${1s}^{-1\mathrm{}}{3a}_1^{\prime }{A}_1^{\prime }$ state.