2005/10/22 by Paolo Umari, P. Umari, A. J. Williamson +3
Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Dielectric #Diffusion Monte Carlo #Extrapolation #Hamiltonian (control theory) #Hybrid Monte Carlo #Markov chain Monte Carlo #Mathematics #Monte Carlo method #Physics #Quantum #Quantum Monte Carlo #Quantum mechanics #Quantum, superfluid, helium dynamics #Spectroscopy and Quantum Chemical Studies #Statistical physics #Wave function #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevlett.95.207602
5 page 2figures
arxiv created 2005/10/22 · openalex publication_date 2005/11/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a novel approach that allows us to calculate the dielectric response of periodic systems in the quantum Monte Carlo formalism. We employ a many-body generalization for the electric-enthalpy functional, where the coupling with the field is expressed via the Berry-phase formulation for the macroscopic polarization. A self-consistent local Hamiltonian then determines the ground-state wave function, allowing for accurate diffusion quantum Monte Carlo calculations where the polarization's fixed point is estimated from the average on an iterative sequence, sampled via forward walking. This approach has been validated for the case of an isolated hydrogen atom and then applied to a periodic system, to calculate the dielectric susceptibility of molecular-hydrogen chains. The results found are in excellent agreement with the best estimates obtained from the extrapolation of quantum-chemistry calculations.