@article{bajdich_mitas_drobny_wagner_schmidt_2006, title={Pfaffian pairing wave functions in electronic-structure quantum Monte Carlo simulations}, volume={96}, ISSN={["1079-7114"]}, DOI={10.1103/physrevlett.96.130201}, abstractNote={We investigate the accuracy of trial wave functions for quantum Monte Carlo based on Pfaffian functional form with singlet and triplet pairing. Using a set of first row atoms and molecules we find that these wave functions provide very consistent and systematic behavior in recovering the correlation energies on the level of 95%. In order to get beyond this limit we explore the possibilities of multi-Pfaffian pairing wave functions. We show that a small number of Pfaffians recovers another large fraction of the missing correlation energy comparable to the larger-scale configuration interaction wave functions. We also find that Pfaffians lead to substantial improvements in fermion nodes when compared to Hartree-Fock wave functions.}, number={13}, journal={PHYSICAL REVIEW LETTERS}, author={Bajdich, M and Mitas, L and Drobny, G and Wagner, LK and Schmidt, KE}, year={2006}, month={Apr} }