“…Diatomic rubidium, Rb 2 , one of the heavy homonuclear alkali metal diatomic molecules, has provided superb systems for molecular spectroscopy, [1][2][3][4][5][6][7][8] photodissociation dynamics, [8][9][10][11] photoassociation spectroscopy, 12,13 and theoretical study of the electronic states. [14][15][16][17] For the ground and several excited electronic states below the Rb(5s) + Rb(5p) atomic limit (X 1 Σ g + , 2 1 Σ g + , 1 1 Π u , and 1 1 Π g ), potential energy curves have been experimentally determined. [1][2][3][4] For the higher-lying excited electronic states, Tsi-Ze ´and San-Tsiang observed the 2 1 Π u state near 475 nm and the 3 1 Π u state near 430 nm by measuring molecular fluorescence in a high-temperature steel tube.…”