“…7 included the absorption band of MoO 2 + . But the absorption band of pentavalent molybdenum species exists at over 25,000 cm À1 in borate glasses [21,22] and the MoO 3 contained in glass has broad absorption bands at 10,000-25,000 cm À1 [23,24]. Therefore, the absorption of molybdenum species does not exist in 5000-9000 cm À1 , and the absorption in 5000-9000 cm À1 is due to UO 2 + .…”