Using first principles calculations we have systematically investigated the structural, electronic and vibrational properties of HfS 2 monolayers in both hexagonal (1H) and trigonal (1T) phases.
The structural stability and electronic properties of the adsorption characteristics of several toxic gas molecules (NH 3 , SO 2 and NO 2 ) on a germanene monolayer were investigated using density functional theory (DFT) based on an ab initio method.