Active material for battery, nonaqueous electrolyte battery, battery pack, and method for manufacturing active material for battery

In general, according to one embodiment, an active material for battery includes a monoclinic complex oxide. The monoclinic complex oxide is expressed by the general formula Li x M1M2 2 O (7±´) (wherein M1 is at least one element selected from the group consisting of Ti, Zr, Si, and Sn, M2 is at least one element selected from the group consisting of Nb, V, Ta, Bi, and Mo, 0 ¤ x ¤ 5, and 0 ¤ ´ ¤ 0.3), and has symmetry belonging to the space group C2/m (International tables Vol. A No. 12), and one element of the M2 or M1 being maldistributed in the occupied 2a and 4i sites in a crystal of the monoclinic complex oxide.