Long-range potentials for theX¹Σ⁺anda³Σ⁺states of the NaK molecule

Abstract

Fluorescence spectra of the NaK molecule excited by the 4765/~ and 4880,~ lines of an argon-ion laser have been recorded at high resolution by Fourier-transform spectrometry. Constants for the ground state X IE+ and for the first excited state, a 3E+, have been determined from a simultaneous least-squares fit to a total of 1758 lines assigned to five systems. Rotationless potentials for these two states have been calculated at internuclear distances out to about 9"3 .~ for the ground state and to about 9"1 ,~ for the triplet state. The dissociation energy, D e (NaK), is found to be 5274'9 + 0'5 cm-1, and the long-range potential for X 15-+ is given by V(r) = -(12"865 + 0"094) x 106/r 6 --(2"760 + 0"011) x 10S/r s -(0.718 + 0"038) x 101~ 1~ --8-70 x 106 exp (--1-664r), with V in cm -1, r in A. Values of the potential constants are in satisfactory agreement with the results of recent calculations.

Spin–orbit coupling of the NaK 33Π and 31Π states: Determination of the coupling constant and observation of quantum interference effects

“…Calculated level energies are then compared to the measured energies and the parameters are varied until the calculated and measured energies agree in the least squares sense. In our present work we fixed the spectroscopic constants T v , B v , D v , and q v of the 3 1 P(v = 6) state to the values reported in the erratum to Laub et al [11] (but corrected for the slight difference between the ground state constants of Ross et al [69] and the more accurate, recent values of Russier et al [70]). In general, the 3 1 P state constants of Pashov et al [66] are probably superior to those of Laub et al, but the latter were chosen for the present work because they cover the same range of vibrational and rotational levels as those investigated here and are also based upon the same calibration.…”

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

“…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.…”

High-precision calculations of van der Waals coefficients for heteronuclear alkali-metal dimers

“…[30] (diamond). [34] 2519(10) a Ishikawa et al, [38] 2646(31) a Ross et al, [39] 2669.4(20) a a Experiment.…”