Experimental studies of the NaK 1 3Δ state

Abstract

The NaK 1 3 ⌬ state has been studied by the perturbation-facilitated optical-optical double resonance technique. Mixed singlet-triplet levels, A(2) 1 ⌺ ϩ (v A ,J)ϳb(1) 3 ⌸(v b ,J), were pumped from thermally populated rovibrational levels of the ground state, X(1) 1 ⌺ ϩ (v X ,JϮ1), using a single-mode cw dye laser. A single-mode cw Ti:Sapphire laser was then used to further excite the NaK molecules to various 1 3 ⌬(v ⌬ ,N ⌬ ,J ⌬ ) rovibrational levels which were detected by observing collision-induced 3 ⌳→a(1) 3 ⌺ ϩ fluorescence in the green part of the spectrum. The measured energies of the 1 3 ⌬(v ⌬ ,N ⌬ ) levels were fit to a Dunham expansion, and the Dunham coefficients were used to construct the RKR potential curve. Absolute numbering of the 1 3 ⌬ state vibrational levels was established by a comparison of experimental and calculated 1 3 ⌬(v ⌬ ,N ⌬ ,J ⌬ ) ←b(1) 3 ⌸(v b ,J b ) absorption line strengths. A deperturbation program was used to determine the vibration-dependent 1 3 ⌬ state spin-orbit interaction parameter. Hyperfine structure of the 1 3 ⌬ state was studied, and the Fermi-contact interaction term for this state was determined to be ϳ0.0111 cm Ϫ1 .

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

“…We use a single-mode cw dye laser (the ''pump'' laserCoherent model 699-29) to excite NaK molecules from a selected ro-vibrational level of the molecular ground state 1(X) 1 R + to the ''intermediate state'', which is a level of the 2(A) 1 R + electronic state or a level with mixed 1(b) 3 P X $ 2(A) 1 R + character [8,9,12,14,15]. The mixed levels 1(b) 3 …”

“…Heteronuclear alkali molecules have permanent dipole moments and are, therefore, of particular interest because, in principle, they can be oriented in an optical lattice [1][2][3][4][5][6][7]. In our laboratory at Lehigh University we have carried out a series of high-resolution spectroscopic studies of various excited electronic states of the heteronuclear alkali diatomic molecule NaK [8][9][10][11][12][13][14][15][16][17]. We have been particularly interested in the fine and hyperfine structure of these states and how variations in these structures with vibrational and rotational quantum numbers reflect changes in the electronic wavefunction with internuclear separation.…”

Structures and charge distributions of cationic and neutral Li X (X = Na and K)

“…However the laboratory spectroscopy has not yet been well explained due to the lack of the reliable information of their geometrical and electronic structures. Despite the geometrical arrangements of Li n Na m (n + m < 5) have been studied [18][19][20][21][22][23][24][25], their electronic charge distributions have not been reported. Deshpande et al [28,29] studies Li n Na and Na n Li (0 < n < 13) clusters with ab initio molecular dynamic method, however, the reliable geometrical structures and charge distributions of these clusters have not been given due to the limitation of the molecular dynamic methods.…”

“…In recent years a large number of binary clusters of lithium with some metallic or nonmetallic elements including sodium, aluminum, fluorine etc have been produced by laser vaporization of various lithium targets in high vacuum [18][19][20][21][22]26,27]. However the laboratory spectroscopy has not yet been well explained due to the lack of the reliable information of their geometrical and electronic structures.…”

“…2, 8, 18, 20, etc. Many theoretical calculations have been carried out for alkali metal clusters, however, most studies were focused on the pure alkali metal clusters [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], nevertheless much less is known for the mixed Li-Na or Li-K clusters [18][19][20][21][22][23][24][25].…”