Methods used to construct spectroscopic line lists using variational treatments of the nuclear motion problem are described. Extensive line line lists are being computed, as part of the ExoMol project for hot atmospheres such as those belong to exoplanets or cool stars, for which completeness is essential, and for high precision studies of our own atmosphere where it is found that ab initio theory can predict transition intensities competitve with the best laboratory measurements. Our procedure involves using potential energy surfaces (PESs) fitted using observed spectroscopic data, ab initio dipole moments surfaces (DMSs) and accurate treament of the nuclear motion problem performed with especially developed and highly-tuned variational codes. For high accuracy treatments, studies using different PESs and DMSs can be used to provide precise, a priori uncertainty quantification of the resulting intensities. As a results, theoretical predictions are beginning to replace laboratory measurements as the source of primary data in well-used atmospheric databases such as HITRAN.

Calculating accurate spectra for the terrestrial and hot atmospheres

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.