Assessing the accuracy of quantum Monte Carlo and density functional theory for energetics of small water clusters

• Published in: The Journal of chemical physics Vol. 136; no. 24; p. 244105
• Main Authors: Gillan, M. J., Manby, F. R., Towler, M. D., Alfè, D.
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics (AIP) 28.06.2012
• Subjects: INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

We present a detailed study of the energetics of water clusters (H2O)n with n ⩽ 6, comparing diffusion Monte Carlo (DMC) and approximate density functional theory (DFT) with well converged coupled-cluster benchmarks. We use the many-body decomposition of the total energy to classify the errors of DM...