Eur. Phys. J. D 65, 105-111 (2011)
https://doi.org/10.1140/epjd/e2011-20048-9

Regular Article

Stark effect measurements on the NaK molecule

¹ Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
² Laboratoire Aimé Cotton, CNRS, Bât. 505, Université Paris-Sud 11, 91405 Orsay Cedex, France

^a e-mail: knoeckel@iqo.uni-hannover.de

Received: 19 January 2011
Received in final form: 18 April 2011
Published online: 23 June 2011

Abstract

In a newly built molecular beam apparatus we have measured permanent electric dipole moments of the B ¹Π and X ¹Σ⁺ states of NaK to test the vibrational dependence of the dipole moment function as predicted by ab initio calculations by Aymar and Dulieu [J. Chem. Phys. 122, 204302 (2005)]. Four vibrational bands were studied, the dipole moment for the B ¹Π decreases from 2.73(2) D for v = 3 to 1.99(2) D for v = 13. The vibrational dependence shows a fairly good agreement with theory, but the absolute values are lower than those from the calculation by 13%. The ground state dipole moment of 2.72(6) confirms the earlier result by Wormsbecher et al. [J. Chem. Phys. 74, 6983 (1981)].