The OH stretching frequency in liquid water simulations: the classical error
✍ Scribed by Lars Ojamäe; Kersti Hermansson; Michael Probst
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 383 KB
- Volume
- 191
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
OH stretching frequencies of HDO molecules in liquid water have been calculated by molecular dynamics simulation and compared to quantum-corrected OH stretching frequencies. In the MD simulation the MCY intermolecular water-water potential was used together with an experimental intramolecular free water potential. The frequencies calculated classically by Fourier transformation of the velocity autocorrelation function are found to be ~ 300 cm-~ too high compared with experiment. Quantum corrections show that the classical error contribution to this discrepancy is ~ 140 cm-1. To reach full agreement with experiment, also the potential model needs to be improved. It is suggested that in constructing flexible water potentials the goal should not be set for an MD-derived OH frequency in absolute agreement with experiment (at 3400 cm-1 ) but instead some 200 cmhigher.
📜 SIMILAR VOLUMES
Spectral diffusion in the OH stretching (m OH ) band of water is studied by ultrafast IR-Raman spectroscopy. The m OH transition consists of two overlapping inhomogeneously broadened subbands, a broader ($500 cm À1 ) redshifted band and a smaller, narrower ($200 cm À1 ) blueshifted band. The blueshi
A classical molecular dynamics (CMD) study has been carried out to investigate the OH stretching spectrum of liquid water. The potential used is the simple point charge model modified to include anharmonic vibrational potentials. A series of CMD runs were made for a system of 100 water molecules. Sp