arXiv subjects

Shan Xi Tian

Publications and source records attributed to Shan Xi Tian.

4 recordsLinked to original sources

arXiv2015

Coherent Resonances Observed in the Dissociative Electron Attachments to Carbon Monoxide

Succeeding our previous finding about coherent interference of the resonant states of CO^- formed by the low-energy electron attachment [Phys. Rev. A 88, 012708 (2013)], here we provide more evidences of the coherent interference, in particular, we find the state configuration change in the interference with the increase of electron attachment energy by measuring the completely backward distributions of the O^- fragment ion of the temporary CO^- in an energy range 11.3-12.6 eV. Therefore, different pure states, namely, coherent resonances, can be formed when the close-lying resonant states are coherently superposed by a broad-band electron pulse.

physics.atm-clus↗

arXiv2012

Imaging the indirect dissociation dynamics of temporary negative ion: N2O- -> N2 + O-

We reported an imaging study of the dissociation dynamics of temporary negative ion N2O- formed in the low-energy electron attachment, e- + N2O -> N2O- -> N2 + O-. With the help of ab initio molecular dynamics calculations, the evolution of momentum distributions of the O- fragment in terms of the electron attachment energy is identified as the result of a competition between two distinctly different indirect pathways, namely, climbing over and bypassing the energy ridge after the molecular structure bending. These two pathways prefer leaving the N2 fragment at the high vibrational and rotational states, respectively.

physics.chem-ph↗

arXiv2011

Renner-Teller Effect on Dissociative Electron Attachments to Carbon Dioxide

Stereo-dynamics of dissociative electron attachments to CO_2 is investigated by the O^- anion velocity imaging experiments combined with the R-matrix calculations. ^2Π_g as a Feshbach resonant state of CO_2^- is confirmed to play roles in the dissociations around 8.0 eV. We find that the dynamic evolutions of the Renner-Teller effect lead to the dramatically different anisotropic O^- momentum distributions.

physics.chem-ph↗

arXiv2008

Steric Effect in Threshold Photoionization Dissociations of Serine Conformers

Steric effect in the threshold dissociative ionizations of serine conformers [CH2OH-C\alphaH(NH2)-C\betaOOH] is revealed by high-level ab initio calculations combined with our newly developed infrared laser desorption / tunable VUV photoionization mass spectrometry. We find that near the ionization thresholds the Cα-Cβand Cα-C bonds are selectively broken for the respective cationic conformers, yielding the different fragments. Novel dynamic processes, proton transfer and reorientation between the predissociative fragments, are involved in the threshold photoionization dissociations.

physics.chem-ph↗