## FIRST HIGH RESOLUTION SPECTROSCOPIC STUDY OF THE $X^{2}\Pi_{\Omega}$ ELECTRONIC STATE OF $HI^{+}$: FINE AND HYPERFINE STRUCTURE ANALYSIS OF THE VIBRATION-ROTATIONAL SPECTRUM

##### Publisher:

Ohio State University##### Abstract:

Prior to this investigation, the spectroscopic information on $HI^{+}$ molecular ion was limited to that obtained from low resolution work using photoelectron techniques. A vibration-rotation study has now been carried out of the $X^{2}\Pi_{\Omega}$ electronic state of $Hl^{+}$ in an a.c. glow discharge using a diode laser spectrometer with velocity modulation. A total of more than 100 transitions belonging to the $(\nu^{\prime} \leftarrow \nu^{\prime\prime}) = (1 \leftarrow 0)$ and $(2 \leftarrow 1)$ vibrational bands of the $^{2}\Pi_{3/2}$ spin substate and to the $(1 \leftarrow 0)$ vibrational band of the $^{2}\Pi _{1/2}$ spin substate have been recorded in the frequency range from $1990 cm^{-1}$ to $2260 cm^{-1}$ for J up to 15.5. At an estimated rotational temperature of the discharge of about 700K, the observed full width at half maximum was $0.004 cm^{-1}$. Large hyperfine splittings arising from magnetic dipole and electric quadurpole interactions have been observed for low J transitions belonging to both of the $\Pi$ substates. Precise values of hyperfine and fine structure constants as well as the vibrational and rotational constants were obtained. Preliminary values for the most important constants are listed below. Vibration-rotation constants: \begin{eqnarray*} \begin{array}{llll} \omega_{e} = 2195.2425(19)cm^{-1},& B_{e} = 6.33077(69) cm^{-1},& P_{e} = 3.5202(40) cm^{-1},& q_{e} = -0.0038(10) cm^{-1}\\ \omega_{e} x_{e} = 39.5970(10) cm^{-1}, & \alpha_{B} = 0.17540(43)cm^{-1}, &\alpha_{p} = 0.0498(23) cm^{-1} \end{array} \end{eqnarray*} Hyperfine coupling constants: \begin{eqnarray*} \begin{array}{ll} a + \frac{1}{2} (b+c) = 0.05112(7) cm^{-1},& d = 0.09945(51) cm^{-1}\\ 1 - \frac{1}{2} (b+c) = 0.0983(96)cm^{-1},& \epsilon Q_{qo} = -.02377(57) cm^{-1} \end{array} \end{eqnarray*} Details of the experiment and the fitted molecular parameters will be presented.

##### Description:

Author Institution: Department of Physics, University of British Columbia

##### Type:

article##### Other Identifiers:

1994-TE'-02Items in Knowledge Bank are protected by copyright, with all rights reserved, unless otherwise indicated.