ACTIVE MATERIAL, NONAQUEOUS ELECTROLYTE BATTERY, BATTERY PACK AND VEHICLE

According to one embodiment, there is provided an active material includes particles of a Na-containing niobium titanium composite oxide having an orthorhombic crystal structure. A peak intensity I 1 of a strongest peak P 1 within a range of 3350 to 3450 cm -1 is 1.6 or less in an infrared diffuse reflectivity spectrum of a surface of the particles, according to a diffuse reflectance Fourier transform spectrometry measurement.