First-order properties and Buckingham birefringence of N₂O and OCS – A computational (re)investigation

Abstract

Prompted by recent experimental reinvestigations of the Buckingham birefringence of CO, CO₂, OCS and N₂O, we have carried out our own reinvestigation of the relevant first- and second-order properties entering the electric-field-gradient-induced birefringence effect of N₂O and OCS by means of state-of-the-art quantum chemical methods. The computed and experimentally derived results remain at significant variance, also in consequence of a remarkable disagreement between the ab initio and the experimental values of the quadrupole moment relative to the centre of the nuclear masses.

Keywords:

• first-order properties
• dipole moments
• quadrupole moments
• electric-field-gradient birefringence

Acknowledgements

This work is dedicated to Prof. Peter R. Taylor on the occasion of his 60th birthday. SC acknowledges support from the PRIN2009 funding scheme, ‘Modelli teorici per processi di fotoassorbimento e foto-emissione’. This work has been supported in Bologna by the PRIN2009 project “Spettroscopia Molecolare per la ricerca Atmosferica ed Astrochimica: Esperimento, Teoria ed Applicazione” and by the University of Bologna (RFO funds).