A Lagerqvist

The Low Lying Electronic States of SiO

Perturbations in the A1Π state of the isotopic 28Si16O and 28Si18O molecules are analyzed. The perturbing states, d3Δr, e3Σ-, C1Σ-, and D1Δ, are identified and vibrationally assigned. Two independent methods of vibrationally numbering the perturbers, employing isotope shifts and vibrational variation of perturbation matrix elements, respectively, are described in detail and shown to be in complete agreement. Molecular constants for the eight lowest energy electronic states of SiO are presented. Semiempirical and isovalent relationships between spin-orbit and spin-spin constants are discussed.

Rotational Analysis of Yellow and Near Infrared Bands in ThO

Three new systems in the molecular spectrum of ThO have been rotationally analysed. They are located in the yellow region of the spectrum. Two bands at 5600 and 5615 A are the 0-0 and 1-1 bands of a system named P-H. One band at 5613 A is another 0-0 band of a system called O-H. The states O and P both have Ω = 0 with different symmetries. Another band at 5579 A is also analysed. Its position in the term scheme of ThO is unknown. New measurements and an extended analysis of the previously investigated G-H transition have been performed. A term scheme and a table of molecular constants for all known states in ThO is given.

New Absorption Systems of the Si2 Molecule in the Vacuum Ultraviolet Region

Two new band systems attributed to the Si2 molecule have been obtained in absorption in flash discharges in SiH4. They are situated in the region 1 840-1 900 ?. They are here designated O 3?u- - X 3?g- and P 3?g - D 3?u. Rotational and vibrational constants have been derived for the O 3?u- state. The 1-0 band of the N 3?u--X 3?g- system at 2118 ? has been reinvestigated.

The Spectrum of CuO: Low Lying Electronic States Observed by Laser Induced Fluorescence

The spectrum of gas phase CuO in the red and near infra-red wavelength region is studied by the laser induced fluorescence technique. Three new low lying electronic states, αΣ, γ2Πi and δ2 Σ, with the approximate T0 values αΣ 15 424 cm-1 γ2Π1/2 15 470 cm-1 γ2Π3/2 15 166 cm-1 δ2 Σ 12 986 cm-1 are reported. The multiplicity of the αΣ is uncertain. It is tentatively considered to be a quartet. The vibrational constants of the δ2 Σ state are ωe ~ 661 cm-1 and ωexe ~ 5.7 cm-1. Earlier results on the spectrum of CuO are reviewed. Intensity anomalies, originating from interference between groups of states, are discussed.

The Low Lying Electronic States of GeO

The A 1Π-X 1Σ+ band system in 74Ge16O and 74Ge18O is analyzed and the local perturbations of the A 1Π state are assigned. Four new electronic states are reported, namely the d 3Δ, e 3Σ-, C 1Σ- and D 1Δ states. Vibrational numbering is determined from the isotopic shifts. The vibrational variations of the perturbation matrix elements are shown to be in agreement with single configuration arguments. The electronic spin-orbit parameter a+ and the Coriolis parameter b are determined. The molecular constants for the eight lowest electronic states are reported. Semi-empirical and isovalent relationships between spin-orbit and spin-spin constants are also discussed. The equilibrium constants for the A 1Π state and the four perturbing states are in cm-1: State Te ωe Be A 1Π 37 763.1 648.8 0.414 32 D 1Δ 32 715 591 0.362 2 C 1Σ- 32 475 591 0.362 2 e 3Σ- 32 214 600 0.362 2 d 3Δ1 30 492 597 0.362 2

The spectra of 74Ge16O and 74Ge18O in the vacuum ultraviolet region

Five band systems of the absorption spectra of the two isotopic molecules 74Ge16O and 74Ge18O in the vacuum ultraviolet region have been rotationally and vibrationally analyzed. A number of perturbations have been observed and from one of these, rotational constants for the perturbing state have been derived. Molecular constants of the upper states are given.

The Spectrum of CuO: Rotational Analysis of Some Green Bands

Two band systems of the emission spectrum of CuO in the green region have been rotationally analyzed, nameley the C 2Πi-X 2Πi and D 2Δi-X 2Πi systems. Molecular constants of the states are given.

A Grating Order Sorter for Separation of High Orders in a 5 m Fastie Vacuum Spectrograph. Some new results concerning the spectra of AlH and AlD

This paper deals with the construction of a grating order sorter for high orders in a 5 m Fastie plane grating vacuum spectrograph. Some parts of the AlH and AlD spectra have been photographed in order to test the order sorter. A rather unique 1?+ - 1?+ perturbation in AlD is discussed.

The Spectrum of CuO: Rotational Analysis of a 4Σ1/2 - 2Π1/2 Transition

Two bands at 4432 A and 4558 A, recognized as the 0-0 and 0-1 transitions of a 4Σ1/2-2Π1/2 system in the emission spectrum of CuO, have been rotationally analyzed. The transition is designated k 4Σ1/2-X 2Π1/2. Molecular constants of the upper state are given.

The Spectrum of ThO: Rotational Analysis of the L1Π-X1Σ+ and N1Π-X1Σ+ Systems

Two new systems of ThO have been rotationally analysed. The systems are assigned L 1?-X 1?+ and N 1?-X 1?+. They are located at about 4020 ? and 3605 ?. In both systems the 0-0 and 1-1 bands have been studied. Molecular constants are given. All upper levels are somewhat perturbed.