The fundamental rotational interval of para-H2 (+) by MQDT-assisted Rydberg spectroscopy of H2

Christa Haase; Maximilian Beyer; Christian Jungen; Frédéric Merkt

doi:10.1063/1.4907531

The fundamental rotational interval of para-H2 (+) by MQDT-assisted Rydberg spectroscopy of H2

J Chem Phys. 2015 Feb 14;142(6):064310. doi: 10.1063/1.4907531.

Authors

Christa Haase¹, Maximilian Beyer¹, Christian Jungen², Frédéric Merkt¹

Affiliations

¹ Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland.
² Laboratoire Aimé Cotton, CNRS, Université Paris-Sud 11, ENS-Cachan, Campus d'Orsay Bâtiment 505, 91405 Orsay, France.

PMID: 25681909
DOI: 10.1063/1.4907531

Abstract

Transitions from selected nd Rydberg states of H2 to n'p/f Rydberg series converging on the lowest two (N(+) = 0 and 2) rotational levels of the X(+) (2)Σg (+) (v(+) = 0) ground state of para-H2 (+) have been measured in the range 1-7.4 THz using a laser-based, pulsed, narrow-band source of submillimeter-wave radiation. The analysis of the spectra by multichannel quantum-defect theory (MQDT) has allowed a complete interpretation of the fine structures of the Rydberg series and their dependence on the principal quantum number. The extrapolation of the series to their limits with MQDT has enabled the determination of the first rotational interval of para-H2 (+), which is 174.236 71(7) cm(-1) (5 223 485.1(2.3) MHz).