Bo Lindgren

The 3Π0u ← X 3Δ1g band system of jet‐cooled Ti2

A band of jet‐cooled 48Ti2 has been located in the near infrared by resonant two‐photon ionization spectroscopy. Rotational analysis has shown the band to be an Ω’=0±←Ω‘=1 transition, which is consistent with the 3Δg ground state proposed by Bauschlicher et al. [J. Chem. Phys. 95, 1057 (1991)]. The band is assigned as a 3Π0u ← X 3Δ1g transition, and lower and upper state bond lengths have been determined as r0(X 3Δg)=1.9422±0.0008 A and r0(3Πu)=1.997±0.009 A (1σ error limits, corrected for spin–uncoupling effects). Comparisons are made to the TiV and V2 molecules, a rationale for the unusual filling order of the 3d‐based molecular orbitals is provided, and molecular orbital assignments are considered for the excited 3Πu state.

The near-infrared spectrum of the FeH molecule

The rotational analysis has been carried out on seven bands of the 4 Delta-4 Delta system of the FeH molecule. In order of wavelength of the heads they are (2-0) at 7786 A, (1-0) at 8692 A, (2-1) at 9020 A, (0-0) at 9896 A, (1-1) at 10253 A, (0-1) at 11939 A, and (1-2) at 12389 A. Molecular constants, term values, spin splittings, and Lambda-type doublings have been derived. Calculated wavelengths and wavenumbers are presented for the (2-2) and (0-2) bands with heads at 10639 and 14927 A, respectively. Finding lists of lines in the observed bands are provided to aid in astronomical applications. 19 references.

The 3Δu−X3Δg band system of jet-cooled Ti2

Abstract Jet-cooled Ti 2 has been observed around 9100 cm −1 using the resonant two-photon ionisation technique. A band at 9097 cm −1 has been analysed as a 3 Δ 1u ← X 3 Δ 1g transition while a weaker structure at 9093 cm −1 has tentatively been labelled 3 Δ 2u ←X 3 Δ 2g .

The rotational structure of the (8, 3) band of the A2Πu-X2Σg+ system of N2+ studied by velocity modulation laser spectroscopy

Abstract The absorption spectrum of the (8, 3) band of the A 2 Π u - X 2 Σ g + system of N 2 + has been recorded using the velocity modulation technique. Rotational constants for the upper vibrational level were derived and rotational and translational temperatures of the discharge plasma were determined.

Rotational Analysis of the Near-Infrared System of the ZrO+ Molecule

Two bands in the emission spectrum from a Zr arc in air, with band heads near 780 nm and 820 nm have been analyzed as the two (0, 0) sub-bands of the A2Π-X2Σ+ system of ZrO+. Rotational analysis of the 90ZrO+ species yields the following constants: for the X2Σ+ state, B0 = 0.437 98 cm-1, D0 = 3.34 × 10-7 cm-1 and for the A2Π state, T0 = 12 499.30 cm-1, A0 = 595.258 cm-1, B0 = 0.409 45 cm-1, D0 = 3.43 × 10-7 cm-1. Observations are also reported for the 92ZrO+ and 94ZrO+ species.

Emission spectra of TiH and TiD near 938 nm

High resolution, near infrared emission spectra of TiH and TiD have been recorded with a Fourier transform spectrometer. The TiH and TiD molecules were made in a titanium hollow cathode lamp operated with a mixture of neon and hydrogen or deuterium gases. A heavily perturbed band system near 938 nm is assigned as a 4Φ–X 4Φ electronic transition. Line positions and approximate spectroscopic constants are reported for the 0–0 band of the new transition. The 4Φ–X 4Φ TiH transition might potentially be observed in late M-type stars and in L-type brown dwarfs.

Diffuse spectra of SeH and SeD

Abstract Diffuse spectra attributed to SeH and SeD have been observed in the 3000–3250 A region. From these observations the ground state dissociation energy can be estimated to D 0 ″ = 3.2 ± 0.2 eV.

A study of the (9,4) and (11,5) bands of the A2Πu-X2Σg+ system and the (1,5) band of the B2Σu+-X2Σg+ system of N2+ by velocity modulation laser spectroscopy

Abstract The velocity modulation laser absorption technique was employed to obtain the spectrum of the (9,4) band of the A2Πu-X2Σg+ system of N2+ and a rotational analysis was performed. The (11,5) band of the A-X system and the (1,5) band of the B2Σu+-X2Σg+ were recorded, and a study of the interaction between the upper states could be performed with a small correlation to the lower state. Deperturbed constants and interaction parameters were derived. The wavenumbers of the rather broad rotational lines and of overlapping lines were determined using a computer program for line profile fitting and decomposition.

On the 1 μm system of iron hydride

Abstract The 987.7 nm system of FeD has been shown by rotational analysis of the (1,0) and (0,0) bands to be due to a 4Δ-4Δ electronic transition. The bond lengths in the ν = 0 levels of the upper and lower states are ro4 = 0.1705 nm and ro11=0.1589 nm. respectively and the (ν′= 1) - (ν′ = 0) vibrational interval of the upper state is 1035 cm−1.

Reaction of small carbon clusters with hydrogen during laser vaporization of graphite

The hydrogen uptake for small carbon clusters C4 to C22 has been studied at high hydrogen pressure. This study indicate that both chain and ring structures exist in parallel.