Diffusion quantum Monte Carlo study of the equation of state and point defects in aluminum

Abstract

The many-body diffusion quantum Monte Carlo (DMC) method with twist-averaged boundary conditions is used to calculate the ground-state equation of state and the energetics of point defects in fcc aluminum using supercells up to 1331 atoms. The DMC equilibrium lattice constant differs from experiment by 0.008 A, or 0.2%, while the cohesive energy using DMC with backflow wave functions with improved nodal surfaces differs by 27 meV. DMC-calculated defect formation and migration energies agree with available experimental data, except for the nearest-neighbor divacancy, which is found to be energetically unstable, in agreement with previous density functional theory (DFT) calculations. DMC and DFT calculations of vacancy defects are in reasonably close agreement. Self-interstitial formation energies have larger differences between DMC and DFT, of up to 0.33eV, at the tetrahedral site. We also computed formation energies of helium interstitial defects where energies differed by up to 0.34eV, also at the tetrahedral site. The close agreement with available experiments demonstrates that DMC can be used as a predictive method to obtain benchmark energetics of defects in metals.

References in corpus (7)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Continuum variational and diffusion quantum Monte Carlo calculations
• Twist-averaged Boundary Conditions in Continuum Quantum Monte Carlo
• Inhomogeneous backflow transformations in quantum Monte Carlo calculations
• Finite-size errors in continuum quantum Monte Carlo calculations
• Fundamental high pressure calibration from all-electron quantum Monte Carlo calculations
• Systematic reduction of sign errors in many-body calculations of atoms and molecules

Cited by in corpus (22)

• Active Learning of Uniformly Accurate Inter-atomic Potentials for Materials Simulation
• QMCPACK : An open source ab initio Quantum Monte Carlo package for the electronic structure of atoms, molecules, and solids
• Cohesion Energetics of Carbon Allotropes : Quantum Monte Carlo Study
• Quantum Monte Carlo applied to solids
• Deep learning inter-atomic potential model for accurate irradiation damage simulations
• Ab initio quantum Monte Carlo calculations of spin superexchange in cuprates: the benchmarking case of Ca${}_2$CuO${}_3$
• Discovering correlated fermions using quantum Monte Carlo
• Point-Defect Optical Transitions and Thermal Ionization Energies from Quantum Monte Carlo Methods: Application to F-center Defect in MgO
• Structural Stability and Defect Energetics of ZnO from Diffusion Quantum Monte Carlo
• First-principles investigation on diffusion mechanism of alloying elements in dilute Zr alloys
• Towards a systematic assessment of errors in diffusion Monte Carlo calculations of semiconductors: case study of zinc selenide and zinc oxide
• Diffusion quantum Monte Carlo calculations of SrFeO${}_3$ and LaFeO${}_3$
• Quantum Monte Carlo analysis of a charge ordered insulating antiferromagnet: the Ti${}_4$O${}_7$ Magnéli phase
• Systematic Comparison and Cross-validation of Fixed-Node Diffusion Monte Carlo and Phaseless Auxiliary-Field Quantum Monte Carlo in Solids
• On the accuracy of the HSE hybrid functional to describe many-electron interactions and charge localization in semiconductors
• Minimum Energy Pathways via Quantum Monte Carlo
• Delayed Slater determinant update algorithms for high efficiency quantum Monte Carlo
• Calculation of the energies of the multideterminant states of the nitrogen vacancy center in diamond with quantum Monte Carlo
• Theoretical Insights into Non-Arrhenius Behaviors of Thermal Vacancies in Anharmonic Crystals
• An efficient hybrid orbital representation for quantum Monte Carlo calculations
• Detection of odor quality and ripening stage of Mangifera indica L. by graphdiyne nanosheet -- a DFT outlook
• Enhanced Twist-Averaging Technique for Magnetic Metals: Applications using Quantum Monte Carlo