- ID:
- ivo://CDS.VizieR/J/MNRAS/446/2337
- Title:
- ExoMol line lists for phosphine (PH_3_)
- Short Name:
- J/MNRAS/446/2337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comprehensive hot line list is calculated for ^31^PH_3_ in its ground electronic state. This line list, called SAlTY, contains almost 16.8 billion transitions between 7.5 million energy levels and it is suitable for simulating spectra up to temperatures of 1500K. It covers wavelengths longer than 1um and includes all transitions to upper states with energies below hc.18000cm^-1^ and rotational excitation up to J=46. The line list is computed by variational solution of the Schrodinger equation for the rotation-vibration motion employing the nuclear-motion program TROVE. A previously reported ab initio dipole moment surface is used as well as an updated 'spectroscopic' potential energy surface (PES), obtained by refining an existing ab initio surface through least-squares fitting to the experimentally derived energies. Detailed comparisons with other available sources of phosphine transitions confirms SAlTY's accuracy and illustrates the incompleteness of previous experimental and theoretical compilations for temperatures above 300K. Atmospheric models are expected to severely underestimate the abundance of phosphine in disequilibrium environments, and it is predicted that phosphine will be detectable in the upper troposphere of many substellar objects. This list is suitable for modelling atmospheres of many astrophysical environments, namely carbon stars, Y dwarfs, T dwarfs, hot Jupiters and solar system gas giant planets. It is available in full as supplementary data to the article and at www.exomol.com.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/471/5025
- Title:
- ExoMol line lists for ^28^SiH_4_
- Short Name:
- J/MNRAS/471/5025
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A variationally computed ^28^SiH_4_ rotation-vibration line list applicable for temperatures up to T=1200K is presented. The line list, called OY2T, considers transitions with rotational excitation up to J=42 in the wavenumber range 0-5000cm^-1^ (wavelengths {lambda}>2um). Just under 62.7 billion transitions have been calculated between 6.1 million energy levels. Rovibrational calculations have utilized a new 'spectroscopic' potential energy surface determined by empirical refinement to 1452 experimentally derived energy levels up to J=6, and a previously reported ab initio dipole moment surface. The temperature-dependent partition function of silane, the OY2T line list format, and the temperature dependence of the OY2T line list are discussed. Comparisons with the PNNL spectral library and other experimental sources indicate that the OY2T line list is robust and able to accurately reproduce weaker intensity features. The full line list is available from the ExoMol database and the CDS database.
- ID:
- ivo://CDS.VizieR/J/MNRAS/434/1469
- Title:
- ExoMol line lists for SiO
- Short Name:
- J/MNRAS/434/1469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate rotation-vibration line lists are calculated for silicon monoxide. Line lists are presented for the main isotopologue, ^28^Si^16^O, and four monosubstituted isotopologues ^29^Si^16^O, ^30^Si^16^O, ^28^Si^17^O and ^28^Si^18^O, in their ground electronic states. These line lists are suitable for high temperatures (up to 9000K) including those relevant to exoplanetary atmospheres and cool stars. A combination of empirical and ab initio methods is used: the potential energy curves are determined to high accuracy by fitting to extensive data from analysis of both laboratory and sunspot spectra; a high quality ab initio dipole moment curve is calculated at the large basis set, multi-reference configuration interaction (MRCI) level. A partition function plus full line lists of rotation-vibration transitions are made available in an electronic form as supplementary data to this article and at www.exomol.com.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/3890
- Title:
- ExoMol line lists for SO2
- Short Name:
- J/MNRAS/459/3890
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion 32S16O2 vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000cm^-1^ (wavelengths longer than 1.25um) for temperatures below 2000K. Infrared absorption cross sections are recorded at 300 and 500C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.
- ID:
- ivo://CDS.VizieR/J/MNRAS/472/3648
- Title:
- ExoMol line lists. PO and PS spectra
- Short Name:
- J/MNRAS/472/3648
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Comprehensive line lists for phosphorus monoxide (PO) and phosphorus monosulphide (PS) in their X2Pi electronic ground state are presented. The line lists are based on new ab initio potential energy (PEC), spin-orbit (SOC) and dipole moment (DMC) curves computed using the MRCI+Q-r method with aug-cc-pwCV5Z and aug-cc-pV5Z basis sets. The nuclear motion equations (i.e. the rovibronic Schroedinger equations for each molecule) are solved using the program Duo. The PECs and SOCs are refined in least-squares fits to available experimental data. Partition functions, Q(T), are computed up to T=5000K, the range of validity of the line lists. These line lists are the most comprehensive available for either molecule. The characteristically sharp peak of the Q-branches from the spin-orbit split components give useful diagnostics for both PO and PS in spectra at infrared wavelengths. These line lists should prove useful for analysing observations and setting up models of environments such as brown dwarfs, low-mass stars, O-rich circumstellar regions and potentially for exoplanetary retrievals. Since PS is yet to be detected in space, the role of the two lowest excited electronic states (a4Pi and B2Pi) are also considered. An approximate line list for the PS X - B electronic transition, which predicts a number of sharp vibrational bands in the near ultraviolet, is also presented. The line lists are also available from the ExoMol (www.exomol.com) database.
5836. ExoMol line lists. SiS
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/1520
- Title:
- ExoMol line lists. SiS
- Short Name:
- J/MNRAS/477/1520
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SiS has long been observed in the circumstellar medium of the carbon-rich star IRC+10216 CW Leo. Comprehensive and accurate rotation-vibrational line lists and partition functions are computed for 12 isotopologues of silicon sulphide in its ground electronic state. The calculations employ an existing spectroscopically accurate potential energy curve (PEC) derived from experimental measurements and a newly-computed ab initio dipole moment curve (DMC).
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/270
- Title:
- ExoMol line lists. Spectra of SH and NS
- Short Name:
- J/MNRAS/478/270
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line lists for sulphur containing molecules SH (the mercapto radical) and NS are computed as part of the ExoMol project. These line lists consider transitions within the ground electronic state for isotopologues of SH and NS. Ab initio potential energy (PEC), and spin-orbit coupling (SOC) curves are computed and then improved by fitting to experimentally observed transitions. Fully ab initio dipole moment curves (DMCs) computed at the high level of theory are used to produce the final line list. For SH, our fit gives a root-mean-square (rms) error of 0.03cm^-1^ between the observed (v_max_=4, J_max_=34.5) and calculated transitions wavenumbers; this is extrapolated such that all possible X bound states are considered. For ^32^SH the resulting line list contains about 81,000 transitions and 2300 rovibronic states, considering levels up to vmax=14 and Jmax=60.5. For NS the refinement using a combination of experimentally-determined frequencies and derived energy levels rms errors of 0.002cm^-1^ and 0.03cm^-1^, respectively. Each NS calculated line lists includes around 3.2 million transitions and 31000 rovibronic states with a vibrational range up to v=53 and rotational range to J=235.5 which covers up to 39000cm^-1^. Both line lists should be complete for temperatures up to 5000K. Example spectra simulated using this line list are shown and comparisons made to the existing data in the CDMS database.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/5324
- Title:
- ExoMol line lists. XXIV. SiH
- Short Name:
- J/MNRAS/473/5324
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SiH has long been observed in the spectrum of our Sun and other cool stars. Computed line lists SiGHTLY for the main isotopologues of silicon monohydride, ^28^SiH, ^29^SiH, ^30^SiH and ^28^SiD are presented. These line lists consider rotation-vibration transitions within the ground X ^2^{Pi} electronic state as well as transitions to the low-lying A ^2^{Delta} and a ^4^{Sigma}^-^ states. Ab initio potential energy (PECs) and dipole moment curves (DMCs) along with spin-orbit and electronic-angular-momentum couplings between them are calculated using the MRCI level of theory with the MOLPRO package. The PEC for the ground X state is refined to available experimental data with a typical accuracy of around 0.01cm^-1^ or better. The ^28^SiH line list includes 11,785 rovibronic states and 1,724,841 transitions with associated Einstein-A coefficients for angular momentum J up to 82.5 and covering wavenumbers up to 31340cm^-1^ (>0.319um). Spectra are simulated using the new line list and comparisons made with various experimental spectra. These line lists are applicable up to temperatures of ~5000K, making them relevant to astrophysical objects such as exoplanetary atmospheres and cool stars and opening up the possibility of detection in the interstellar medium.
- ID:
- ivo://CDS.VizieR/J/MNRAS/480/3397
- Title:
- ExoMol line lists XXXI: C_2_
- Short Name:
- J/MNRAS/480/3397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate line lists for the carbon dimer, C_2_, are presented. These line lists cover rovibronic transitions between the eight lowest electronic states: X, A, B, B', a, b, c, d. Potential energy curves (PECs) and transition dipole moment curves are computed on a large grid of geometries using the aug-cc-pwCVQZ-DK/MRCI level of theory including core and core-valence correlations and scalar relativistic energy corrections. The same level of theory is used to compute spin-orbit and electronic angular momentum couplings. The PECs and couplings are refined by fitting to the empirical (MARVEL) energies of C_2_ using the nuclear-motion program Duo. The transition dipole moment curves are represented as analytical functions to reduce the numerical noise when computing transition line strengths. Partition functions, full line lists, Lande-factors and lifetimes for three main isotopologues of C_2_ (^12^C_2_, ^13^C_2_ and ^12^C^13^C) are made available.
- ID:
- ivo://CDS.VizieR/J/MNRAS/486/2351
- Title:
- ExoMol line lists. XXXII. MgO
- Short Name:
- J/MNRAS/486/2351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line lists for magnesium oxide are computed and extensive comparisons are made with existing experimental spectra. The LiTY line lists cover all ro-vibration transitions within the five lowest-lying electronic states (X, a, A, B, b) and five isotopologues ^24^Mg^16^O, ^25^Mg^16^O, ^26^Mg^16^O, ^24^Mg^17^O, ^24^Mg^18^O. The calculation use potential energy cures, spin-orbit and electronic angular momentum couplings curves determined by fitting to empirical energy levels which are reproduced to within 0.01cm^-1^ in most cases. The computed wavefunctions combined with ab initio dipole moment curves giving transition intensities and excited state radiative lifetimes which are compared with laboratory measurements. The ^24^Mg^16^O line list comprises 186842 (J<=320) ro-vibronic states and 72833173 transitions with for angular momenta, J, up to 300 and covering energies in wavenumber up to 33000cm^-1^. The line list are suitable for temperatures up to about 5000K. They are relevant to astrophysical studies of exoplanet atmospheres, cool stars and brown drafts.