A first principles molecular dynamics study of vibrational spectral diffusion and hydrogen bond dynamics in liquid methanol

作者：Yadav Vivek K; Karmakar Anwesa; Choudhuri Jyoti Roy; Chandra Amalendu^*

来源：Chemical Physics, 2012, 408: 36-42.

DOI：10.1016/j.chemphys.2012.09.006

• Liquid methanol
• Ab initio molecular dynamics
• Hydrogen bonds
• Spectral diffusion

We present a first principles theoretical study of vibrational spectral diffusion and hydrogen bond dynamics in liquid methanol at room temperature. The dynamics of spectral diffusion of OD modes of deuterated methanol reveals two times scales: a short time scale of about 120 fs and a longer time scale of about 3.2 ps. A damped oscillation is also found at around 120-180 fs. Calculations of power spectrum of relative velocities and hydrogen bond correlation functions reveal that the short time dynamics originates from intermolecular motion of hydrogen bonded methanol pairs while the long time relaxation corresponds to the breaking dynamics of hydrogen bonds. The quantitative details of the time constants are found to depend on the frequency of tagged OD bonds.

• 出版日期2012-10-26