The vacuum ultraviolet absorption spectrum of diatomic calcium

Calcium granules (99.5%) have been heated to 615°C in a tantalum furnace and the absorption spectrum has been observed on the SA 61 beam line of SUFERACO (Orsay) using a 3-metre Balzers monochromator down to the -LiF cut-off (1015 Å). An intense Rydberg series has been observed between 1900 and 1500 Å. This series extends from n = 5 to n = 12 and gives the ionization potential at 63068 cm^?1 (1585.6 Å) or 7.819eV and the quantum defect δ = 1.73.     

Fourier transform infrared spectrum of carbon disulphide in the 4ν2 + ν3 band region near 3100 cm−1

Fourier transform spectra have been recorded for carbon disulphide CS₂ in the region of the 4ν₂ + ν₃ band near 3100 cm^?1. The data analysis has determined new molecular constants. Bands were also observed for the isotopomer ¹²C³²S³⁴S.     

Entropy driven demixing in binary mixtures of hard convex bodies: influence of molecular geometry

The recently introduced approach (Bosetti, H., and Perera, A., 2001, Phys. Rev. E, 63, 021206) for studying entropy driven demixing in binary mixtures of hard convex bodies is applied here to analyse the influence of molecular geometrical factors such as shape and size ratio on isotropic fluid-fluid phase separation. The theory is shown to be self-consistent, in the sense that it allows the calculation of both the binodal and the spinodal of the demixing, and both curves merge at the same lower consolute point. In the case of 3-dimensional fluids, demixing is usually allowed for sufficiently thick solutes, provided no orientational ordering destabilizes the mixture. Fluid—fluid demixing is explicitly forbidden in cases of equal breadth of the solute and the solvent molecules, regardless of the aspect ratio of both particles. In particular, mixtures of prolate and oblate particles will demix more easily. The influence of shape is more importantly seen at moderate elongations. Finally, within the present approximation, demixing is forbidden for binary mixtures of 2-dimensional fluids, irrespective of the shape of the bidimensional molecules.     

Low resolution VUV absorption spectrum of boron monoxide

The absorption spectrum of BO has been recorded between 2400 and 300 Å on the SA61 beam line of SUPERACO in Orsay. A new electronic transition has been observed and vibrationally analysed. Nine Rydberg states have been observed and classified into Rydberg series giving two ionization limits at 12.849eV for the X ¹Σ⁺ ionic state and at 13.117eV for the A ¹II state of BO⁺. Two ionization limits have been observed at 754 and 374 Å. The first of these corresponds to the B ¹Σ⁺ state and the last one to the C ¹Σ⁺ state of BO⁺. The new results are compared with the ab initio calculations of Karna and Grein concerning BO and BO⁺. The agreement is satisfactory.     

Spectra of carbon disulphide in the 3400–4400 cm−1 region by Fourier transform spectroscopy

Fourier transform spectra have been recorded for carbon disulphide (CS₂) in the region between 3400 cm^?1 and 4400 cm^?1. A data analysis has determined new molecular constants: 14 bands were observed for the main isotopic form ¹²C³²S₂, two bands for the isotopomer ¹²C³²S³⁴S and one each for ¹²C³²S³³S and ¹³C³²S₂.