Laser vaporization of berillium: Gas phase spectrum and molecular potential of Be(2).

Berillium diatomic, Be(2) is the third lightest metal diatomic (after li(2) and LiBe). In spite of the simplicity of this system containing only 8 electrons, nothing was known about it experimentally, and theoretical works differed widely in their predictions. In this manuscript we generate Be(2) experimentally by vaporizing Be metal by YAG laser pulses in the presence of cold helium gas. The Be(2) is then probed by a tunable pulsed dye laser and detected by its fluorescence. An intense electronic transition with origin near 27860 cm(-1) is observed and assigned to Be(2). Analysis of the spectrum yields G1/2 = 223.4cm(-1) and r(rho)=2.46 angstrom for the ground electronic state.