Zero-point energy constrained quasiclassical, classical, and exact quantum simulations of isomerizations and radial distribution functions of the water trimer using an ab initio potential energy surface

► The zero-point energy (ZPE) constrained c-QCT method is applied to the water trimer. ► Exact quantum path integral Monte Carlo (PIMC) calculations are performed for (H2O)3. ► The time scale of isomerizations using c-QCT and classical dynamics is different. ► The ZPE is important to get realistic radial distribution functions (RDFs). ► Unlike the classical results the c-QCT RDFs are in good agreement with the PIMC ones.