The luminescence spectrum of the uranyl ion contains no evidence of strong vibronic anharmonicity in the first electronic excited state

The work of Liu and Vikhnin [Chem. Phys. Lett. 437 (2007) 56] on anharmonic charge-transfer vibronic states in uranyl compounds is examined critically. It is concluded that there is currently no experimental evidence to justify the use of a phenomenological model of anharmonic vibronic coupling in these systems.