Pushing the Accuracy Limits of Scalable Fixed-Node Diffusion Monte Carlo for Noncovalent Interactions

Single-determinant (SD) fixed-node diffusion Monte Carlo (FNDMC) gains popularity as a benchmark tool scalable to large noncovalent systems although its accuracy limits are not yet fully mapped out. Some of the recent results suggest that accuracy of SD FNDMC is capable of achieving benchmark accuracy for a rich class of noncovalent systems, larger than expected before. The talk will summarize recent progress and current accuracy limits of bias-cancellation-based SD FNDMC for molecules and noncovalent crystals. The best available "recipe" suitable for a wide class of noncovalent systems will be sketched out.