Quantum corrections for water and other solvents from classical molecular simulations

What is it about?

The (free) energy landscape that determines the propensity and rate of processes, such as chemical reactions, molecular self-assembly, and phase transitions, is routinely sampled with classical molecular dynamics simulations. Although a powerful approach, it neglects quantum effects, such as the zero-point energy, which can be important, for example in computing heat capacities or acidity constants. Here, we show how the zero-point energy can be obtained for solvent molecules from classical simulations by using the vibrational spectrum.

Featured Image

Photo by timJ on Unsplash

Photo by timJ on Unsplash

Why is it important?

The current state of the art to capture quantum effects is by performing computationally expensive path-integral simulations. Our approach uses the 2PT method, which is more approximate, but much less demanding and thus also applicable to larger systems. We show for a range of liquids and several mixtures that the zero-point energy is captured very well compared to quantum chemical calculations.