Vibrational properties of uracil

A semiempirical molecular dynamics model is developed to study the vibrational frequen cies of uracil at very low kinetic temperature by using the Fourier transform of velocity autocorrelation func tion of trajectories of molecular dynamics simulations The finite difference harmonic method is used to as sign the vibrational frequency of each mode. The calculated frequencies are found to be in good agreement with experimental measurements. More over, we make up for the lost vibrational modes in experiments self-consistently. A total of 30 vibrationa modes and their corresponding frequencies are re ported.