The 2 3Πg and 3 3Πg states of 7Li2: Optical–optical double resonance spectroscopy and ab initio calculations

Abstract

Articles you may be interested inHyperfine structures of the 7Li2 b 3Π u , 23Π g , and 33Π g states: Continuous wave perturbation facilitated optical-optical double resonance spectroscopy Perturbation facilitated optical-optical double resonance spectroscopy of the 23Σ+ g , 33Σ+ g , and 43Σ+ g Rydberg states of 7Li2 A pulsed optical-optical double resonance study of the 11Π g state of 7Li2The (2pϩ2p) 2 3 ⌸ g and (2sϩ3 p) 3 3 ⌸ g states of 7 Li 2 have been studied both experimentally and theoretically. Vibrational levels vϭ0 -41 of the 2 3 ⌸ g state and vϭ6 -10 of the 3 3 ⌸ g state have been observed by perturbation facilitated optical-optical double resonance ͑PFOODR͒ spectroscopy. Our ab initio calculations show that the 2 3 ⌸ g state, although dissociating into 2 pϩ2 p atomic limit, is a Rydberg state and strongly mixed with the (2sϩ3p) 3 3 ⌸ g and (2sϩ3d) 4 3 ⌸ g Rydberg states. Our theoretical calculations show good agreement with our experimental results.

Experimental Study of the NaK 31Π State

“…The sodiumpotassium mixture is contained in a crossed heat-pipe oven (at a temperature in the range 357-402°C) using argon as a buffer gas (P ϭ 0.4-1.2 Torr). A single-mode ring dye laser (Coherent model 699-29), using LD700 dye and pumped by a 5 W krypton ion laser, is used as the PUMP laser to excite specific 2( A) 1 …”

“…The second laser (PROBE) is then used to excite these molecules to a higher electronic state. Absorption of the PROBE photon can be monitored by detecting direct fluorescence from the upper level (1)(2)(3)(4), fluorescence from nearby levels of the same or another electronic state populated by collisions (5-9), fluorescence from atomic levels populated by predissociation or collisonal energy transfer (4), ions produced by photoionization or various collisional mechanisms involving the upper level (2, 9 -13), or rotations of the PROBE laser polarization (14 -15). Because only one ro-vibrational level is used as a starting point for this PROBE step, the spectra consist of very simple patterns which allow easy identification of the electronic states involved, as well as the determination of molecular constants.…”

“…We report the results of an optical-optical double resonance experiment to determine the NaK 3 1 ⌸ state potential energy curve. In the first step, a narrow band cw dye laser (PUMP) is tuned to line center of a particular 2(A) 1 ⌺ ϩ (vЈ, JЈ) 4 1(X) 1 ⌺ ϩ (vЉ, JЉ) transition, and its frequency is then fixed.…”

“…In the first step, a narrow band cw dye laser (PUMP) is tuned to line center of a particular 2(A) 1 ⌺ ϩ (vЈ, JЈ) 4 1(X) 1 ⌺ ϩ (vЉ, JЉ) transition, and its frequency is then fixed. A second narrowband tunable cw Ti:Sapphirelaser (PROBE) is then scanned, while 3 1 ⌸ 3 1(X) 1 ⌺ ϩ violet fluorescence is monitored.…”

Study of the Valence and Rydberg States of a Lithium Dimer by the Multi-reference Configuration-interaction Method

“…It is the smallest bound homonuclear molecule beyond H 2 and may serve as a prototype for testing theoretical methods. The first ab initio calculations of Li 2 were performed by Konowalow et al 8 Currently, all-electron ab initio calculations are rarely used [9][10][11] for this molecule, and most theoretical calculations are performed using the effective core potential (ECP) method.…”