We implement the phaseless auxiliary field quantum Monte Carlo method using the plane-wave based projector augmented wave method and explore the accuracy and the feasibility of applying our implementation to solids. We use a singular value decomposition to compress the two-body Hamiltonian and, thus, reduce the computational cost. Consistent correlation energies from the primitive-cell sampling and the corresponding supercell calculations numerically verify our implementation. We calculate the equation of state for diamond and the correlation energies for a range of prototypical solid materials. A down-sampling technique along with natural orbitals accelerates the convergence with respect to the number of orbitals and crystal momentum points. We illustrate the competitiveness of our implementation in accuracy and computational cost for dense crystal momentum point meshes compared to a well-established quantum-chemistry approach, the coupled-cluster ansatz including singles, doubles, and perturbative triple particle-hole excitation operators.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/5.0156657 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Scalable Quantum Monte Carlo with Direct-Product Trial Wave Functions.
J Chem Theory Comput
May 2024
ByteDance Research, Zhonghang Plaza, No. 43, North third Ring West Road, 100098 Beijing, China.
The computational demand posed by applying multi-Slater determinant trials in phaseless auxiliary-field quantum Monte Carlo methods (MSD-AFQMC) is particularly significant for molecules exhibiting strong correlations. Here, we propose using direct-product wave functions as trials for MSD-AFQMC, aiming to reduce computational overhead by leveraging the compactness of multi-Slater determinant trials in direct-product form (DP-MSD). This efficiency arises when the active space can be divided into noncoupling subspaces, a condition we term "decomposable active space".
View Article and Find Full Text PDFMetal-Insulator Transition in a Semiconductor Heterobilayer Model.
Phys Rev Lett
February 2024
Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA.
Transition metal dichalcogenide superlattices provide an exciting new platform for exploring and understanding a variety of phases of matter. The moiré continuum Hamiltonian, of two-dimensional jellium in a modulating potential, provides a fundamental model for such systems. Accurate computations with this model are essential for interpreting experimental observations and making predictions for future explorations.
View Article and Find Full Text PDFScalar Relativistic All-Electron and Pseudopotential Study of a Minimal Nitrogenase [Fe(SH)H] Model Employing Coupled-Cluster and Auxiliary-Field Quantum Monte Carlo Many-Body Methods.
J Phys Chem A
February 2024
Department of Computational Chemistry, Lund University, Chemical Centre, SE-221 00 Lund, Sweden.
Nitrogenase is the only enzyme that can cleave the triple bond in N, making nitrogen available to organisms. The detailed mechanism of this enzyme is currently not known, and computational studies are complicated by the fact that different density functional theory (DFT) methods give very different energetic results for calculations involving nitrogenase models. Recently, we designed a [Fe(SH)H] model with the fifth proton binding either to Fe or S to mimic different possible protonation states of the nitrogenase active site.
View Article and Find Full Text PDFResponse properties in phaseless auxiliary field quantum Monte Carlo.
J Chem Phys
November 2023
Department of Chemistry, University of Colorado, Boulder, Colorado 80302, USA.
We present a method for calculating first-order response properties in phaseless auxiliary field quantum Monte Carlo by applying automatic differentiation (AD). Biases and statistical efficiency of the resulting estimators are discussed. Our approach demonstrates that AD enables the calculation of reduced density matrices with the same computational cost scaling per sample as energy calculations, accompanied by a cost prefactor of less than four in our numerical calculations.
View Article and Find Full Text PDFExpanding the Design Space of Constraints in Auxiliary-Field Quantum Monte Carlo.
J Chem Theory Comput
November 2023
Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States.
We formulate and characterize a new constraint for auxiliary-field quantum Monte Carlo (AFQMC) applicable for general fermionic systems, which allows for the accumulation of phase in the random walk but disallows walkers with a magnitude of phase greater than π with respect to the trial wave function. For short imaginary times, before walkers accumulate sizable phase values, this approach is equivalent to exact free projection, allowing one to observe the accumulation of bias associated with the constraint and thus estimate its magnitude . We demonstrate the stability of this constraint over arbitrary imaginary times and system sizes, highlighting the removal of noise due to the fermionic sign problem.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!