Solid State Calculations - QMC for Materials - Session 5 of 7

Learn to perform Quantum Monte Carlo calculations for materials and solid-state systems using QMCPACK, Quantum ESPRESSO, and Nexus in this comprehensive tutorial delivered by Raymond Caly. Master the fundamental concepts of modeling materials with periodic boundary conditions and understand how to address finite-size effects that arise in both DFT and QMC calculations. Explore advanced techniques including twist averaging procedures, grand canonical twist averaging, and methods for correcting two-body finite size effects through structure factor and KZK corrections. Discover how to construct and optimize wavefunctions for solid-state systems, including splined orbitals and hybrid representations. Follow a systematic checklist for conducting QMC calculations on solids and apply your knowledge through a hands-on lab exercise focusing on bulk carbon diamond. The session covers essential topics from basic periodic boundary conditions through advanced correction methods, providing both theoretical understanding and practical implementation guidance for materials science applications using quantum Monte Carlo methods.