Supplementary Material

The Supplementary Material contains the results of the density profiles of lipid headgroup atoms and hydration shell water and variation of peak heights of the total and dissected 1D-VSFG spectra with tempera-ture. The timescales of the decay of slope of the nodal line (SNL) of 2D-VSFG spectra and frequency fluctuation time correlation function (FFTCF) are also included in the Supplementary Materials.