Anharmonic vibrational resonances in small water clusters

Numerical calculations of structures and vibrational spectra of small water clusters are performed by solution of the molecular Schrodinger equation in the density functional theory framework using B3LYP and X3LYP hybrid functionals. Spectral features and evolution of hydrogen bond properties in clusters with their size increasing are discussed. The vibrotational Hamiltonian parameters and Fermi and Darling–Dennison anharmonic resonances in small water oligomers are determined. Obtained results may be used in quantum mechanics/molecular dynamics simulations of water and processes in active site of enzyme.