Electronic states and spin-forbidden cooling transitions of AlH and AlF

Nathan Wells, Ian C. Lane

Research output: Contribution to journalArticlepeer-review

68 Citations (Scopus)


The feasibility of laser cooling AlH and AlF is investigated using ab initio quantum chemistry. All the electronic states corresponding to the ground and lowest two excited states of the Al atom are calculated using multi-reference configuration interaction (MRCI) and the large AV6Z basis set for AlH. The smaller AVQZ basis set is used to calculate the valence electronic states of AlF. Theoretical Franck-Condon factors are determined for the A(1)Pi -> X(1)Sigma(+) transitions in both radicals and found to agree with the highly diagonal factors found experimentally, suggesting computational chemistry is an effective method for screening suitable laser cooling candidates. AlH does not appear to have a transition quite as diagonal as that in SrF (which has been laser cooled) but the A(1)Pi -> X(1)Sigma(+) transition transition of AlF is a strong candidate for cooling with just a single laser, though the cooling frequency is deep in the UV. Furthermore, the a (3)Pi -> X(1)Sigma(+) transitions are also strongly diagonal and in AlF is a practical method for obtaining very low final temperatures around 3 mu K.
Original languageEnglish
Pages (from-to)19018-19025
Number of pages8
Journal Physical Chemistry Chemical Physics
Issue number42
Early online date12 Aug 2011
Publication statusPublished - 2011

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • General Physics and Astronomy


Dive into the research topics of 'Electronic states and spin-forbidden cooling transitions of AlH and AlF'. Together they form a unique fingerprint.

Cite this