SearcharxivSearch

arXiv subjects

Patrick Crozet

Publications and source records attributed to Patrick Crozet.

2 recordsLinked to original sources

ExoMol line lists -- LXV. Mid-Infrared rovibronic spectroscopy of isotopologues of NiH

New line lists for four isotopologues of nickel monohydride, $^{58}$NiH, $^{60}$NiH, $^{62}$NiH, and $^{58}$NiD are presented covering the wavenumber range $<10000$ cm$^{-1}$ ($\lambda > 1$ $\mu$m), $J$ up to 37.5 for transitions within and between the three lowest-lying electronic states, ${X}\,^{2}\Delta$, ${W}\,^{2}\Pi$, and ${V}\,^{2}\Sigma^{+}$. The line lists are applicable for temperatures up to 5000 K. The line lists calculations are based on a recent empirical NiH spectroscopic model [Havalyova et al. J. Quant. Spectrosc. Radiat. Transf., 272, 107800, (2021)] which is adapted for the variational nuclear-motion code Duo. The model consists of potential energy curves, spin-orbit coupling curves, electronic angular momentum curves, spin-rotation coupling curves, $\Lambda$-doubling correction curve for $^2\Pi$ states and Born-Oppenheimer breakdown (BOB) rotational correction curves. New ab initio dipole moment curves, scaled to match the experimental dipole moment of the ground state, are used to compute Einstein A coefficients. The BYOT line lists are included in the ExoMol database at www.exomol.com.

astro-ph.SR

The spectrum of N$_2$ from 4,500 to 15,700 cm$^{-1}$ revisited with PGOPHER

Using a reference molecular atlas to ensure self-consistency of wavelength calibration is widespread practice. Boesch \& Reiners (Astronomy \& Astrophysics 582 A43 (2015)) reported a line list from a discharge of molecular nitrogen from 4500 to 11000 cm$^{-1}$ for this purpose. With a hollow-cathode discharge source, we have extended the experimental spectrum up to 15700 cm$^{-1}$, to include the range of Ti:sapphire lasers, since the density of N 2 lines is greater than atomic atlases in common use. Recognizing that experimental conditions can vary, we have also analysed the spectra (comprising several B ${}^3Π_g-A\ {}^3Σ_u^+$ , B' ${}^3Σ_u - B\ {}^3Π_g$, and W ${}^3Δ_u-B\ {}^3Π_g N_2$ bands) with standard Hamiltonians, so that any part of the discharge spectrum 4500-15700 cm$^{-1}$ can be simulated. Parameters are given to do this with the spectral simulation and analysis package PGOPHER. (C. Western, J. Quant. Spectrosc. Rad. Transf., 186, 221 (2016)). The analysis also included high-level ab initio calculations of potential energy curves, transition moments and spin-orbit coupling constants and these were used in preparing the model, extending the potential range of applicability. The results are available in a variety of formats to suit possible applications, including the experimental spectrum in ASCII, a detailed line list with positions and Einstein A coefficients, and a PGOPHER input file to synthesize the spectrum at selectable temperature and resolution. 2

physics.chem-ph