A study of the cost-effectiveness of Jastrow correlation factor forms in real-space quantum Monte Carlo methods

In real-space Quantum Monte Carlo simulations, the Jastrow factor in the Slater-Jastrow ansatz is the primary way of including electron correlation beyond mean-field wavefunctions. The Jastrow factor improves the trial and guiding wavefunctions in variational and diffusion Monte Carlo in both accuracy and efficiency. The Jastrow factor may include several terms to capture different types of correlation. One type of terms is formulated as functions of distances between particles for example electron-ion, electron-electron, electron-electron-ion and even electron-electron-ion-ion terms. K-space term potentially captures the nature of periodicity in solids. In this work, we investigate how Jastrow factor terms individually and collectively impact the quality of many-body wavefunction in molecules and solids with light and transition metal elements. We also study the cost of each type of terms to help making cost-effective choices in QMC simulations.