Periodic Reporting for period 1 - Rmat3 (Theoretical study of cold and ultracold collisions in triatomic systems using inner-region nuclear motion wavefunctions and outer-region R-matrix propagation)
Reporting period: 2016-07-01 to 2018-06-30
The problem being addressed in this proposal is the lack of computational tools available to model the collisions of ultracold atoms and diatomics which strongly interact. These collisions are intrinsically quantum mechanical; slight changes in the speed of the collision can cause radically different results. This research is extremely timely as it ties in with current research within the experimental physics community. The overall objective of this project is to combine progress in computationally modelling spectroscopy of triatomic systems with approaches to model electrons colliding with molecular systems. Substantial progress has been made towards developing this new computational methodology, including addressing various unexpected theoretical challenges.
The theoretical underpinnings of the proposed algorithm design were developed extensively, with complete implementations in the diatomic case and initial implementation in the more complex triatomic case. The treatment of a finite region Schrodinger equation proved much more difficult than anticipated; in particular, the boundary conditions required was unexpected, but yielded great insight into the heavily utilised R-matrix technique. We found a solid choice of basis set for this problem, implemented it within the DVR3D program and achieved promising results for model systems and HOCl. Two publications have so far resulted, with additional publications in preparation. Further, this work was presented at international conferences.
This project provides a novel computational approach to the field of ultracold molecular physics, which will enable scientists to elucidate the unusual reactions that occur in this quantum dominated regime.