Double Excitation Energies from Quantum Monte Carlo Using State-Specific Energy Optimization
Stuart Shepard, Ramón L. Panadés‐Barrueta, Saverio Moroni, Anthony Scemama, Claudia Filippi
Abstract
We show that recently developed quantum Monte Carlo methods, which provide accurate vertical transition energies for single excitations, also successfully treat double excitations. We study the double excitations in medium-sized molecules, some of which are challenging for high-level coupled-cluster calculations to model accurately. Our fixed-node diffusion Monte Carlo excitation energies are in very good agreement with reliable benchmarks, when available, and provide accurate predictions for excitation energies of difficult systems where reference values are lacking.
Topics & Concepts
Monte Carlo methodQuantum Monte CarloExcitationDiffusion Monte CarloPhysicsDynamic Monte Carlo methodStatistical physicsCoupled clusterMonte Carlo molecular modelingEnergy (signal processing)Computational physicsMoleculeQuantum mechanicsMarkov chain Monte CarloMathematicsStatisticsAdvanced Chemical Physics StudiesQuantum, superfluid, helium dynamicsCatalytic Processes in Materials Science