The spectroscopy of H⁺₃ : low energy to dissociation

• Main Author: Ramanlal, Jayesh
• Published: University College London (University of London) 2005
• Subjects: 546.26
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414203

The H⁺₃ ion is the simplest and most fundamental of polyatomic molecules consisting of three protons and two electrons. H⁺₃ is an important molecule playing a key role in many areas of Physics, Chemistry and Astronomy. The astrophysical importance of H⁺₃ lies in the fact that most of the universe is made up of hydrogen, and molecular hydrogen in the cool regions. H⁺₃ is rapidly formed by the reaction H₂+H⁺₂→H⁺₃+H. Thus H⁺₃ is usually the dominant ion in environments containing molecular hydrogen. Furthermore, multiple deuterated species have been observed in the interstellar medium recently. These species are thought to have been formed via deuterium fractionation effects, in which the isotopomers H₂D⁺ and D₂H⁺ play a significant role. More than two decades have passed since Carrington and co-workers produced a remarkably rich spectrum of the H⁺₃. Over 27,000 absorption lines in a region between 872cm⁻¹ to 1094cm⁻¹. This experiment still remains largely unexplained. This work calculates intensities of transitions of states near dissociation. Thus will help illuminate the Carrington spectrum. Within this work I present a method of calculating line strengths for the H⁺₃ system. Several improvements on previous methods are presented, including the use of discrete variable representation, symmetry and a parallel algorithm. The implementation of this method on massively parallel computers is also discussed. Several applications of the synthetic spectra of H⁺₃ and isotopomers are presented. This will include where possible how they have aided other work and the results of this other work.