The c 3Σ+, b 3Π, and a 3Σ+ states of NaK revisited

Abstract

The NaK 1 ( b ) Π Ω = 0 3 state hyperfine structure and the 1 ( b ) Π Ω = 0 3 2 ( A ) Σ + 1 spin-orbit interaction J. Chem. Phys. 122, 074306 (2005); 10.1063/1.1844293 High resolution spectroscopy and channel-coupling treatment of the A 1 Σ + -b 3 Π complex of NaRbWe present new c 3 ⌺ ϩ →a 3 ⌺ ϩ laser induced fluorescence spectra of the NaK molecule, which clearly indicate that v 0 ϭ20 is the first vibrational level of the c 3 ⌺ ϩ state lying above vϭ0 of B 1 ⌸ state. These spectra are used in a multistep deperturbation (B 1 ⌸ϳc 3 ⌺ ϩ ϳb 3 ⌸) procedure to obtain improved a 3 ⌺ ϩ , b 3 ⌸ and c 3 ⌺ ϩ potential energy curves. The deperturbation analysis is confirmed by the calculated electronic B 1 ⌸ϳc 3 ⌺ ϩ and c 3 ⌺ ϩ ϳb 3 ⌸ spin-orbit matrix elements obtained from many-body multipartitioning perturbation theory employing the relativistic effective potential method.

Global analysis of data on the spin-orbit-coupledA1Σu+andBai1, Ahmed2, Beser3 et al. 2011Phys. Rev. ASelf Cite

“…Recently, the methods available for analyzing and modeling spectroscopic data on highly perturbed states have been extended [18][19][20][21][22][23][24][25][26][27] As is evident from the discussion below, each effort to perform a "global analysis" of all available data on these two electronic states raises additional questions about what Hamiltonian elements and functions are required, and what data is required to determine the parameters so as to achieve a fit with residuals comparable to experimental uncertainties. There has been impresssive progress in data acquisition and analysis for the heteronuclear A and b states from work on NaK [28][29][30][31][32] to more recent work on NaRb [19,23], NaCs [24], KCs [25,26], and RbCs [21,27]. For NaRb, NaCs, and KCs, vibrational assignments of both states have been reliably determined, and the perturbative interactions have been modeled to an accuracy of 0.01 cm −1 or better.…”

Multichannel modeling and two-photon coherent transfer paths in NaK

“…The final PECs used in our calculation are shown in Fig. 5 (dashed lines) together with the RKR curves obtained from [11][12][13] (solid lines), showing satisfactory agreement.…”

“…Ab initio curves provided by quantum chemistry calculations [21] give a complete overall description of the PEC, which, however, is accompanied by lower total accuracy. The desired states have also been investigated by means of molecular spectroscopy [11][12][13]. Out of these measurements, spectroscopic constants can be extracted and RKR curves constructed.…”

“…To avoid mixing theoretical and semi-empirical descriptions, we decided to follow a different path described below, taking the ab initio curves of [25] and refine them by using our fully explored ground state potentials. The RKR potentials [11][12][13] are then employed together with spectroscopic data as a crosscheck for the spectroscopically known regions.…”

“…A large number of experimental data and spectroscopic constants are available in the literature, leading e.g. to the potential energy curves (PECs) of the involved electronic states [9][10][11][12][13], and are supplemented by sophisticated theoretical studies of molecular properties like radiative lifetimes, dipole moments or static polarizabilities [14,15]. Recently, Feshbach resonances have been observed [16] and ultracold fermionic 23 Na 40 K Feshbach molecules created subsequently [17].…”