The absorption spectrum of the BeH and BeD molecules in the vacuum ultraviolet

Absorption spectra of the BeH and BeD molecules have been studied in the vacuum ultraviolet using beryllium metal heated in a King furnace filled with 1 atm of hydrogen or deuterium gas. The band system at 1960 A has been extended and in the region of 1900 to 1700 A a number of new band systems have been found and analyzed rotationally. A strong band at 1850 A has been identified as resulting from a transition to a 3d complex (D state). The B, E, F, and D states are Rydberg states yielding an ionization potential of 66 200 +- 500 cm-1. The B state, which has a double minimum potential energy curve, and the G state form a pair of states which result from an avoided crossing. A precise value of the ground state dissociation energy is derived. (author)