Observation and analysis of the SF6 v2 + v4-v5 band: Improved parameters for the v5=1 state

In this paper, we present the high resolution analysis of the weak v(2) + v(4) - v(5) band of SF6 around 735 cm(-1). The spectra were recorded on the AILES Beamline at the SOLEIL Synchrotron facility using a cryogenic multipass cell coupled to a Bruker 125HR spectrometer with a maximum resolution of 0.00102 cm(-1). For this band, we worked with 4 mbar of SF6 at a temperature of 223 2 K. The optical path length was fixed to 141 m and the spectrum recorded with 0.001 cm(-1) of resolution. A new, cold spectrum of the v(2) + v(4) band was also collected at 153 K, 15-m path length, and 0.0015 cm(-1) resolution. The analysis was performed by using the Dijon group XTDS and SPVIEW software, based on tensorial formalism. We achieved correct simulation and line position assignments of the v(2) + v(4) - v(5) band, by gathering v(2) + v(4) data and v(5) Raman data. We could assign 3553 transition for v(2) + v(4) - v(5) with a standard deviation of 1.292 x 10(-3) cm(-1). This analysis also helped improve the v(2) = v(4) =1 level and the v(5) = 1 fundamental level v(2) = v(4) =1. (C) 2016 Elsevier Inc. All rights reserved.