Structure and dynamics of H${}_2^{+}$ near the dissociation threshold: a combined experimental and computational investigation

Abstract

The pulsed-field-ionization zero-kinetic-energy photoelectron spectrum of H${}_2$ has been recorded in the vicinity of the dissociative-ionization threshold following three-photon excitation via selected rotational levels of the B ${}^1{\Sigma }_u^{+}$ ($v=19$) and $\bar{\mathrm{H}}$ ${}^1{\Sigma }_g^{+}$ ($v=11$) intermediate states. The spectra consist of transitions to bound levels of the X${}^{+}$ ${}^2{\Sigma }_g^{+}$ state of H${}_2^{+}$ with $v^{+}$ in the range 14-19 and $N^{+}$ in the range 0-9, of the A${}^{+}$ ${}^2{\Sigma }_u^{+}$ state with $v^{+}=0$ and $N^{+}=0-2$, and of shape resonances corresponding to the X${}^{+}(v^{+}=17,N^{+}=7)$ and X${}^{+}(v^{+}=18,N^{+}=4)$ quasibound levels. Calculations of the level structure of H${}_2^{+}$ have been carried out and the influence of adiabatic, nonadiabatic, relativistic and radiative corrections on the positions of these levels, and in the case of the shape resonances also on their widths, has been investigated. Different methods of calculating the widths and profiles of the shape resonances have been tested for comparison with the experimental observations. Slow oscillations of the dissociative-ionization yield have been observed and reflect, in first approximation, the Franck-Condon factors of the $\bar{\text{H}}$ $\to$ X${}^{+}$, A${}^{+}$ bound - free transitions.

References in corpus (3)

• Test of the theoretical hyperfine structure of the molecular hydrogen ion at the 1-ppm level
• Relativistic corrections of mα^6(m/M) order to the hyperfine structure of the H_2^+ molecular ion
• Observation and calculation of the quasi-bound rovibrational levels of the electronic ground state of H${}_2^{+}$

Cited by in corpus (9)

• Ro-vibrational states of H${}_2^{+}$. Variational calculations
• Precise computation of rovibronic resonances of molecular hydrogen: $EF{}^1{\Sigma }_{\mathrm{g}}^{+}$ inner-well rotational states
• Non-adiabatic mass correction to the rovibrational states of molecules. Numerical application for the H${}_2^{+}$ molecular ion
• Non-adiabatic mass correction for excited states of molecular hydrogen: improvement for the outer-well $H\bar{H}{}^1{\Sigma }_{\mathrm{g}}^{+}$ term values
• Vibronic mass computation for the $EF$-$GK$-$H\bar{H}$ ${}^1{\Sigma }_{\text{g}}^{+}$ manifold of molecular hydrogen
• Regularized relativistic corrections for polyelectronic and polyatomic systems with explicitly correlated Gaussians
• Precision measurement of quasi-bound resonances in H${}_2$ and the H + H scattering length
• Highly accurate potential energy curves for the hydrogen molecule ion
• Structure and dynamics of HD${}^{+}$ in the vicinity of the H${}^{+}$ + D and D${}^{+}$ + H dissociation thresholds: Feshbach resonances and the role of g/u-symmetry breaking