High-resolution emission spectra of MgH and MgD in the 600 to 850 nm wavelength region

Abstract

The emission spectra from a magnesium dc arc in hydrogen or deuterium have been photographed at high resolution from 600 to 850 nm. Thirteen new bands of MgH and 18 of MgD in the B′ 2 Σ + –X 2 Σ + system have been identified and complete rotational analyses have been performed. Term values have been obtained for all bound ground state rotational levels of MgH for ν = 4–9 and MgD for ν = 6–13 and limiting curves of dissociation have been used to determine the dissociation energy of MgH. The experimental value, D 0 0″ (MgH) = 1.27 ± 0.03 eV is in excellent agreement with theory. The ground state RKR potential curve and Franck–Condon factors for the B′–X system are reported. Data on the isotopic molecules 25 MgH, 26 MgH, 25 MgD, and 26 MgD have also been obtained.