Context <p>Lithium-based compounds, such as Li₂O, Li₂S, Li₃N, and LiF, have important applications in the fields of semiconductors, optics and energy. By performing density functional theory calculations, the structures and properties of lithium-based compounds, including the crystalline, electronic, mechanical, and optical characteristics, were systematically investigated. The impact of oxygen doping on the structure and performance was further studied. The results revealed that doping can reduce their band gaps and elastic constants and change the magnetic properties and the optical moments. These insights can provide theoretical guidance for the design and development of novel lithium-based, sulfide, nitride and fluoride compounds.</p> Methods <p>The calculations were performed using the generalized gradient approximation (GGA) method with Perdew–Burke–Ernzerhof (PBE) functional. The Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional was further used for electronic structure corrections. All computations were performed using VASP program.</p> Graphical Abstract <p></p>