Comment on 'Linear and bent triatomic molecules are not qualitatively different!'

Jensen (Can. J. Phys. 98, 506 (2020). doi: 10.1139/cjp-2019-0395 ) presents theoretical justification for the claim that linear triatomic molecules are necessarily observed to be bent. The basis of the assertion is that the expectation value of the supplement of the bending angle, [Formula: see text] used in Jensen’s paper, is calculated to be positive. In this comment, we examine the interpretation of the expectation values of [Formula: see text] in stationary states, and indicate that Jensen’s claim contradicts a basic principle of quantum mechanics that the energy and geometrical variables cannot have definite values at the same time.