We present here recent methodological developments to enable the accurate treatment of large molecules in quantum Monte Carlo (QMC).  Using the familiar concepts of local orbitals and Lewis resonance structures, we introduce a new class of accurate and compact many-body wave functions specifically designed for the efficient description of ground and excited states in QMC. We demonstrate the performance of our linear-scaling wave functions in QMC calculations of fragmentation energies, barrier heights, reaction energies, and excitation energies. Furthermore, we illustrate the simple and general formalism we have recently developed to compute efficiently interatomic forces and other derivatives in QMC. The computational gain derived from the combination of these concepts is demonstrated on large molecular systems.

Extending the applicability of quantum Monte Carlo methods to large molecules

253rd National Meeting (2017)

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