Comment on: ‘A symmetric hydrogen bond revisited: potassium hydrogen maleate by variable temperature, variable pressure neutron diffraction and plane-wave DFT methods’ [Chem. Phys. Lett. 381 (2003) 102]

In their recent Letter Wilson, Thomas and Morrison [Chem. Phys. Lett. 381 (2003) 102] questioned the hydrogen bonding potential function in potassium hydrogen maleate that was proposed by Fillaux, Leygue, Tomkinson, Cousson and Paulus [Chem. Phys. 244 (1999) 387]. Wilson et al.’s argument is not supported by any new experimental data of significance. Moreover, the plane-wave DFT potential they calculate for the hydrogen bond was determined in a range of little significance to the experimental data. Fillaux et al.’s potential still represents the fullest description of the totality of experimental observations.