## Abstract

The emission spectrum of HfCl has been investigated in the 3000-18 500 cm(-1) region at high resolution using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of HfCl4 and helium. Two bands near 17 140 and 17 390 cm(-1) were also measured in absorption using laser excitation spectroscopy. In this instance the molecules were created by laser ablation in a molecular beam apparatus. The observed bands have been classified into two electronic transitions, [7.6] (4)Delta(3/2)-X(2)Delta(3/2) and [17.1] (2)Delta(3/2)-X(2)Delta(3/2) involving a common lower state. A rotational analysis of the 0-0 and 1-1 bands of [7.6] (4)Delta(3/2)-X(2)Delta(3/2) and 0-0, 1-1, and 1-0 bands of the [17.1] (2)Delta(3/2)-X(2)Delta(3/2) transitions has been carried out and the equilibrium spectroscopic constants have been determined. The ground state principal molecular constants are B-2 = 0, 1097404(54) cm(-1), alpha(e) = 0.0004101(53) cm(-1), and r(e) = 2.290532(57) Angstrom. Ab initio calculations have been performed on HfCl and spectroscopic properties of the low lying electronic states have been predicted. The ground state is predicted to be a regular (2)Delta state arising from the valence electron configuration, 1 sigma(2)sigma(2)3 sigma(2)1 pi(4)1 delta(1). On the basis of our nb initio calculations;. we assign the observed transitions as [7.6](4)Delta(3/2)-X(2)Delta(3/2) and [17.1] (2)Delta(3/2)-X(2)Delta(3/2). (C) 2000 Academic Press.

Original language | English |
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Pages (from-to) | 116-130 |

Number of pages | 15 |

Journal | JOURNAL OF MOLECULAR SPECTROSCOPY |

Volume | 202 |

Issue number | 1 |

Publication status | Published - Jul 2000 |

## Keywords

- TRANSFORM EMISSION-SPECTROSCOPY
- LYING ELECTRONIC STATES
- ROTATIONAL ANALYSIS
- BAND SYSTEM
- S-STARS
- TICL
- IDENTIFICATION
- C-4-DELTA-X-4-PHI
- PSEUDOPOTENTIALS
- MONOFLUORIDE