Related Experiment Video
Updated: May 22, 2026

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
Infrared shifts of the water dimer from the fully flexible ab initio HBB2 potential
1Institut Charles Gerhardt (CTMM)-UMR 5253, CC 1501, Université Montpellier II-CNRS, 34095 Montpellier Cedex 05, France. claude.leforestier@univ-montp2.ft
Abstract:
We report calculations of the infrared shifts for the water dimer, as obtained from the recent ab initio fully flexible HBB2 potential of Bowman and co-workers. The rovibrational calculations, which formally are 12-dimensional plus overall rotation, were performed within the [6+6]d adiabatic separation which decouples the 'fast' intramolecular modes from the 'slow' intermolecular ones. Apart from this decoupling, each set of modes is treated in a fully variational approach. The intramolecular motion was described in terms of Radau coordinates, using the f-embedding formulation of Wei & Carrington, and neglecting the rovibrational Coriolis coupling terms. Within this adiabatic approximation, the intermolecular motion is handled in a similar way as for rigid monomers, except for the rotational constants B's, averaged over intramolecular modes that depend now on the intermolecular geometry. Comparison with experimental data shows an excellent overall agreement.
More Related Videos
Related Concept Videos
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
IR Frequency Region: X–H Stretching
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
IR Absorption Frequency: Hybridization
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to the...
IR Spectrum Peak Intensity: Amount of IR-Active Bonds

