Nature of project: **experimental**, experimental

Available to students on full-time physics degree schemes or joint students.

This project would suit a student who is interested in learning about high-level quantum chemistry methods (MCSCF/MRCI method) and who enjoys coding as the project would involve lots of simulation and analysis.

Doppler laser cooling is the process by which atoms and, more recently, diatomic molecules can be cooled by quasi-cyclic absorption and re-emission of laser-generated photons which are detuned such that they are absorbed by species moving towards the laser.

In this project the primary aim would be to perform quantum chemistry calculations on diatomic molecules which are being tested for laser cooling applications (CaF, MgF, SrF....).

As a baseline I would expect a student to undertake calculations for the ground and several excited states.

*A successful project will develop beyond the above in one/some of the following directions:*

A secondary target would be to calculate the couplings between electronic states (transition dipole, spin orbit, electronic angular momentum).

Another avenue would be computation of a line list using the Duo programme based purely on these calculations.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

*Additional scope or challenge if taken as a Year-4 project:* Calculations for molecules containing transition metals which have high spin.

Please speak to **Maire Gorman** if you consider doing this project.

*Initial literature for students:*

- https://www.molpro.net/
- The ab initio calculation of spectra of open shell diatomic molecules, Tennyson et al. (2016), Journal of Physics B: At. Mol. Opt. Phys., 49
- Ab initio calculations to support accurate modelling of the rovibronic spectroscopy calculations of vanadium monoxide (VO), McKemmish et al. (2016), Molecular Physics 114, 3232
- Laser cooling of a diatomic molecule, Shuman et al. (2010), Nature 467, 820-823

This project will involve using SuperComputing Wales and hence learning how to effectively use the unix command line.

milestone | to be completed by |
---|---|

Basic familiarity with MOLRO | end of October |

Analysis of ground electronic state | Christmas |

Calculations of excited states | end of February |

Analysis of lifetimes | Easter |