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arXiv · 1804.11143

Dissociation energy of the hydrogen molecule at 10$^{-9}$ accuracy

C. Cheng·J. Hussels·M. Niu·H. L. Bethlem·K. S. E. Eikema·E. J. Salumbides·W. Ubachs·M. Beyer·N. J. Hölsch·J. A. Agner·F. Merkt·L. -G. Tao·S. -M. Hu·Ch. Jungen
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Abstract

The ionization energy of ortho-H$_2$ has been determined to be $E^\mathrm{o}_\mathrm{I}(\mathrm{H}_2)/(hc)=124\,357.238\,062(25)$ cm$^{-1}$ from measurements of the GK(1,1)--X(0,1) interval by Doppler-free two-photon spectroscopy using a narrow band 179-nm laser source and the ionization energy of the GK(1,1) state by continuous-wave near-infrared laser spectroscopy. $E^\mathrm{o}_\mathrm{I}$(H$_2$) was used to derive the dissociation energy of H$_2$, $D^{N=1}_{0}$(H$_2$), at $35\,999.582\,894(25)$ cm$^{-1}$ with a precision that is more than one order of magnitude better than all previous results. The new result challenges calculations of this quantity and represents a benchmark value for future relativistic and QED calculations of molecular energies.

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C. Cheng, J. Hussels, M. Niu, H. L. Bethlem, K. S. E. Eikema, E. J. Salumbides, W. Ubachs, M. Beyer, N. J. Hölsch, J. A. Agner, F. Merkt, L. -G. Tao, S. -M. Hu, Ch. Jungen. 2018-04-30. Dissociation energy of the hydrogen molecule at 10$^{-9}$ accuracy. https://doi.org/10.1103/physrevlett.121.013001

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