Vibrational dynamics of the OD stretch in an atomistic simulation of HDO in H2O

•A wavelet-based method was developed to obtain the frequency-frequency correlation functions (FFCFs) of OD in H2O.•Spectral diffusion observed in FFCFs can be primarily attributed to fluctuations in O-O distances.•Obtained OD bond length correlation decay of 1.73 ps, similar to experimental OD vibrational lifetimes from 1.45 ps−1.8 ps.•Simulated OD stretch energy correlation function consists of an exponential decay with a time constant of 1.13 ps.