Further, to investigate the stability of the monolayers, the cohesive energy is calculated by using the above-mentioned relation in section 2. The calculated cohesive energies for CrS 2 , CrSe 2 and Janus CrSSe monolayers are -4.10, -3.59, and -3.83 eV, respectively. The lower value of cohesive energy indicates stronger interactions between the atoms in these monolayers. Hence, the structural stability is in the order of CrS 2 >CrSSe>CrSe 2 . The cohesive energy and the nature of the chemical bonding are closely related. Therefore, to analyze the nature of the bonding, we perform the Mulliken charge density calculations. The charge density contour plot (Fig. ) shows that the charges are accumulated around the Cr atom in all the monolayers. Most of the valence charges are accumulated between Cr and S/Se atoms suggesting the covalent bonding between Cr-X/Y atoms.