A threshold-photoelectron-coincidence spectrum of HBr has been recorded in the 32.2–35.8 eV photon energy range, with a resolution of 0.01 eV, using a synchrotron radiation source. The X triplet Sigma and the a singlet Delta states of the HBr2+ dication are clearly observed in the spectrum, while there is no clear evidence for the formation of the b singlet Sigma+ electronic state. For the first two states, the vibrational states v=0–3 have been resolved, while for the ground X triplet Sigma state also spin–orbit splitting has been detected. The results appear in good agreement with previous experimental observations. A comparison with theoretical predictions indicates the role of ‘‘noncovalent’’ contributions to the interaction between the two atomic partners for the formation of metastable states.
Threshold-photoelectron-spectroscopy-coincidence study of the double photoionization of HBr
BRUNETTI, Brunetto Giovanni;CANDORI, Pietro;FALCINELLI, Stefano;PIRANI, Fernando;VECCHIOCATTIVI, Franco
2004
Abstract
A threshold-photoelectron-coincidence spectrum of HBr has been recorded in the 32.2–35.8 eV photon energy range, with a resolution of 0.01 eV, using a synchrotron radiation source. The X triplet Sigma and the a singlet Delta states of the HBr2+ dication are clearly observed in the spectrum, while there is no clear evidence for the formation of the b singlet Sigma+ electronic state. For the first two states, the vibrational states v=0–3 have been resolved, while for the ground X triplet Sigma state also spin–orbit splitting has been detected. The results appear in good agreement with previous experimental observations. A comparison with theoretical predictions indicates the role of ‘‘noncovalent’’ contributions to the interaction between the two atomic partners for the formation of metastable states.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
