2009/09/02 by Paolo Umari, P. Umari, Nicola Marzari
Physics and Astronomy · #Advanced Chemical Physics Studies #Diffusion #Monte Carlo method #Nonlinear system #Polarization (electrochemistry) #Quantum #Quantum Monte Carlo #Quantum, superfluid, helium dynamics #Spectroscopy and Quantum Chemical Studies #Wave function #physics.chem-ph #physics.comp-ph
paper · pdf · doi:10.1063/1.3213567
9 pages; accepted on J. Chem. Phys
arxiv created 2009/09/02 · openalex publication_date 2009/09/02 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We calculate the linear and nonlinear susceptibilities of periodic longitudinal chains of hydrogen dimers with different bond-length alternations using a diffusion quantum Monte Carlo approach. These quantities are derived from the changes in electronic polarization as a function of applied finite electric field--an approach we recently introduced and made possible by the use of a Berry-phase, many-body electric-enthalpy functional. Calculated susceptibilities and hypersusceptibilities are found to be in excellent agreement with the best estimates available from quantum chemistry--usually extrapolations to the infinite-chain limit of calculations for chains of finite length. It is found that while exchange effects dominate the proper description of the susceptibilities, second hypersusceptibilities are greatly affected by electronic correlations. We also assess how different approximations to the nodal surface of the many-body wave function affect the accuracy of the calculated susceptibilities.