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Abstract: We have theoretically investigated the correlation satellite spectra associated with the single-site (ss) and two-site (ts) double core–hole (DCH) states. The calculated ssDCH satellite spectra of N2 (N 1s−2) and CO (O 1s−2) reproduced the observed experimental spectra satisfactorily and provided the first detailed assignments. DCH spectroscopy using X-ray two-photon photoelectron spectroscopy (XTPPS) was examined taking account of the single core–hole (SCH) and DCH satellite spectra. The results demonstrate that in XTPPS the ssDCH satellite spectrum is separated from other SCH/tsDCH spectra, while the tsDCH states and their satellite states may be overlapped with the SCH satellite spectrum. [Copyright &y& Elsevier]

Abstract: We have investigated the K –2, K –1 L –1, and L –2 double core hole (DCH) states of the SiX4 (X=H, F, Cl, and CH3) molecules using the CASSCF and DFT methods aiming at the DCH electron spectroscopy. The Si 1s IPs and DIPs of the present molecules and the generalized relaxation energies are compared and analyzed. The values extracted from the excess relaxation energy agree well with the generalized relaxation energy. The effect of the substituents (H, F, Cl, and CH3) surrounding the central Si atom is examined. The present results illustrate that the DCH electron spectroscopy for K –2, K –1 L –1, and L –2 DCH states is useful for the chemical analysis. [Copyright &y& Elsevier]

Abstract: Low-energy electron impact excitations of S2 molecules are studied using the fixed-nuclei R-matrix method based on state-averaged complete active space SCF orbitals. Integral cross sections are calculated for elastic electron collision as well as impact excitation of the 7 lowest excited electronic states. Also, differential cross sections are obtained for elastic collision and excitation of the and states. The integrated cross section of optically allowed excitation of the state agrees reasonably well with the available theoretical result. [Copyright &y& Elsevier]

The predissociation rates of 600 vibrationally excited H3 2sA1′ states were obtained by three-dimensional wave packet calculations. Ab initio calculations were carried out for the nonadiabatic coupling matrix elements as well as a quantum defect surface of the H3 2sA1′ state, which were represented in terms of the hyperspherical coordinates to be utilized in the wave packet study. For the 2sA1′ ground vibrational level, the estimated rate agrees well with the experimental value. The mean decay rate increases with vibrational energy, but the distribution largely scatters around the mean rate. An implication of the experiments for higher Rydberg states is given based on the analysis of the present results. [Copyright &y& Elsevier]