Efficient Production of Hot Molecular Line Lists

Molecular line lists are of utmost importance in understanding and characterising the molecular composition of atmospheres from their spectra. Cool stars and exoplanets such as Hot Jupiters have temperature ranges that allow for a significant composition of molecules in their atmospheres with extremely complex and rich spectral structures. Building a comprehensive line-list to model such phenomena is a non-trivial task. Therefore efficient production is a necessity. This thesis presents three molecular line lists produced using the theoretical methodologies of the TROVE program suite. GPU Accelerated Intensities (GAIN) is a new addition to TROVE and allows for the rapid calculation of billions of transitions by exploiting graphics processing units (GPUs) to speed up the evaluation of the line strength by almost 1000x compared to previous codes. The program’s extensive usage in computing the 17 billion transitions for the hot phosphine line list SAlTY is briefly discussed. A hot H2CO line-list applicable to 1500 K is computed using TROVE and GAIN from a refined potential energy surface (PES) and ab initio dipole moment surface (DMS). Results are compared to experimental data and problems encountered from the PES refinement are discussed. A preliminary room temperature line list for H2O2 is produced from a purely ab initio PES and DMS and compared to experimental result. The ab initio PES is then refined to spectroscopic accuracy and a final hot line list is produced applicable up to 1250 K