ACTIVE MATERIAL, NONAQUEOUS ELECTROLYTE BATTERY, BATTERY PACK AND VEHICLE

According to one approach, there is provided an active material. The active material includes particles of a Na-containing niobium titanium composite oxide having an orthorhombic crystal structure. An intensity ratio I 1 /I 2 is within a range of 0.12 ¤ I 1 /I 2 ¤ 0.25 in an X-ray diffraction pattern of the active material, according to X-ray diffraction measurement using a Cu-K± ray. I 1 is a peak intensity of a peak P 1 that is present within a range where 2¸ is 27° to 28°in the X-ray diffraction pattern of the active material. I 2 is a peak intensity of a peak P 2 that is present within a range where 2¸ is 23° to 24° in the X-ray diffraction pattern of the active material.