Abstract
The structural, elastic, electronic and optical properties of the gallium monohydrides BaGaXH (X=Si, Ge, Sn) have been investigated by means of first principles calculations. The low values of the B/G ratio of these compounds correspond to the brittle nature, which is due to the hydrogen presence. The bulk modulus, Young's modulus, shear modulus decrease from Si to Sn for BaGaXH (X=Si, Ge, Sn) in the same column in the periodic table. Also the Debye temperature of these compounds has a relative high θD value indicating that they possess good thermal conductivity. The mean sound velocities have a progressive decrease from silicon (Si) to tin (Sn).