Observation and calculation of the quasi-bound rovibrational levels of the electronic ground state of H${}_2^{+}$

Abstract

Although the existence of quasi-bound rotational levels of the $X^{+}{}^2{\Sigma }_g^{+}$ ground state of H${}_2^{+}$ has been predicted a long time ago, these states have never been observed. Calculated positions and widths of quasi-bound rotational levels located close to the top of the centrifugal barriers have not been reported either. Given the role that such states play in the recombination of H(1s) and H${}^{+}$ to form H${}_2^{+}$, this lack of data may be regarded as one of the largest unknown aspects of this otherwise accurately known fundamental molecular cation. We present measurements of the positions and widths of the lowest-lying quasi-bound rotational levels of H${}_2^{+}$ and compare the experimental results with the positions and widths we calculate using a potential model for the $X^{+}$ state of H${}_2^{+}$ which includes adiabatic, nonadiabatic, relativistic and radiative corrections to the Born-Oppenheimer approximation.

5 pages, 3 figures

References in corpus (2)

• Relativistic corrections of mα^6 order to the ro-vibrational spectrum of H_2^+ and HD^+ molecular ions
• Cosmological production of H_2 before the formation of the first galaxies

Cited by in corpus (7)

• Heteronuclear long-range Rydberg molecules
• Photolysis production and spectroscopic investigation of the highest vibrational states in H${}_2$ (X${}^1{\Sigma }_g^{+}$ $v=13,14$)
• Precision measurement of quasi-bound resonances in H${}_2$ and the H + H scattering length
• Shape resonances in H${}_2$ as photolysis reaction intermediates
• Highly accurate potential energy curves for the hydrogen molecule ion
• Characterization of the electronic ground state of He${}_2^{+}$ by high-resolution photoelectron spectroscopy
• 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