Dataset contains DFT calculations of oxygen-deficient perovskites from the Ca2Fe2O5-brownmillerite and Ca2Mn2O5 structures; and tunnel CaMn4O8, a derivative of the CaMn2O4-marokite with Ca vacancies. The dataset was produced to investigate the effects of oxygen introduction or Ca vacancy introduction in ternary transition metal oxides, as a means to assess potential new Ca-ion battery materials.