Cu2.67 Li1.33 Nb1.33 O12 Ti2.67 Mouron P, Choisnet J Journal of Solid State Chemistry 66 (1987) 311-317 New substituted copper titanates with the Ca Cu3 Ti4 O12 structure: Li (Cu3-x Lix) (Ti3-x M1+x) O12 (M(V)=Nb: 12