User’s Guide and Developer’s Manual

Contents:

• Introduction
  • Quickstart and a first QMCPACK calculation
  • Authors and History
  • Support and Contacting the Developers
  • Performance
  • Open Source License
  • Contributing to QMCPACK
  • QMCPACK Roadmap
• Features of QMCPACK
  • Real-space Monte Carlo
  • Auxiliary-Field Quantum Monte Carlo
  • Supported GPU features for real space QMC
  • Sharing of spline data across multiple GPUs
• Obtaining, installing, and validating QMCPACK
  • Installation steps
  • Obtaining the latest release version
  • Obtaining the latest development version
  • Prerequisites
  • C++ 14 standard library
  • Building with CMake
  • Installation instructions for common workstations and supercomputers
  • Installing via Spack
  • Testing and validation of QMCPACK
  • Automated testing of QMCPACK
  • Building ppconvert, a pseudopotential format converter
  • Installing and patching Quantum ESPRESSO
  • How to build the fastest executable version of QMCPACK
  • Troubleshooting the installation
• Running QMCPACK
  • Command line options
  • Input files
  • Output files
  • Running in parallel with MPI
  • Using OpenMP threads
  • Running on GPU machines
• Units used in QMCPACK
• Input file overview
  • Project
  • Random number initialization
• Specifying the system to be simulated
  • Specifying the Simulation Cell
  • Specifying the particle set
• Trial wavefunction specification
  • Introduction
  • Single determinant wavefunctons
  • Single-particle orbitals
  • Jastrow Factors
  • Multideterminant wavefunctions
  • Backflow Wavefunctions
  • Gaussian Product Wavefunction
• Hamiltonian and Observables
  • The Hamiltonian
  • Pair potentials
  • General estimators
  • Forward-Walking Estimators
  • “Force” estimators
  • Stress estimators
• Quantum Monte Carlo Methods
  • Variational Monte Carlo
  • Wavefunction optimization
  • Diffusion Monte Carlo
  • Reptation Monte Carlo
• Output Overview
  • The .scalar.dat file
  • The .opt.xml file
  • The .qmc.xml file
  • The .dmc.dat file
  • The .bandinfo.dat file
  • Checkpoint and restart files
• Analyzing QMCPACK data
  • Using the qmca tool to obtain total energies and related quantities
  • Using the qmc-fit tool for statistical time step extrapolation and curve fitting
  • Using the qdens tool to obtain electron densities
• Periodic LCAO for Solids
  • Introduction
  • Generating and using periodic Gaussian-type wavefunctions using PySCF
• Selected Configuration Interaction
  • Theoretical background
• Spin-Orbit Calculations in QMC
  • Introduction
  • Single-Particle Spinors
  • Trial Wavefunction
  • QMC Methods
  • Spin-Orbit Effective Core Potentials
• Auxiliary-Field Quantum Monte Carlo
  • Input
  • Hamiltonian File formats
  • Wavefunction File formats
  • Current Feature Implementation Status
  • Advice/Useful Information
  • AFQMCTOOLS
• Examples
  • Using QMCPACK directly
  • Using Nexus
• Lab 1: MC Statistical Analysis
  • Topics covered in this lab
  • Lab directories and files
  • Atomic units
  • Reviewing statistics
  • Inspecting MC Data
  • Averaging quantities in the MC data
  • Evaluating MC simulation quality
  • Reducing statistical error bars
  • Scaling to larger numbers of electrons
• Lab 2: QMC Basics
  • Topics covered in this lab
  • Lab outline
  • Lab directories and files
  • Obtaining and converting a pseudopotential for oxygen
  • DFT with QE to obtain the orbital part of the wavefunction
  • Optimization with QMCPACK to obtain the correlated part of the wavefunction
  • DMC timestep extrapolation I: neutral oxygen atom
  • DMC time step extrapolation II: oxygen atom ionization potential
  • DMC workflow automation with Nexus
  • Automated binding curve of the oxygen dimer
  • (Optional) Running your system with QMCPACK
  • Appendix A: Basic Python constructs
• Lab 3: Advanced molecular calculations
  • Topics covered in this lab
  • Lab directories and files
  • Exercise #1: Basics
  • Generation of a Hartree-Fock wavefunction with GAMESS
  • Exercise #2: Slater-Jastrow wavefunction options
  • Exercise #3: Multideterminant wavefunctions
  • Appendix A: GAMESS input
  • Appendix B: convert4qmc
  • Appendix C: Wavefunction optimization XML block
  • Appendix D: VMC and DMC XML block
  • Appendix E: Wavefunction XML block
• Lab 4: Condensed Matter Calculations
  • Topics covered in this lab
  • Lab directories and files
  • Preliminaries
  • Total energy of BCC beryllium
  • Handling a 2D system: graphene
  • Conclusion
• Lab 5: Excited state calculations
  • Topics covered in this lab
  • Lab directories and files
  • Basics and excited state experiments
  • Preparation for the excited state calculations
  • Quasiparticle (electronic) gap calculations
  • Optical gap calculations
• AFQMC Tutorials
  • Example 1: Neon atom
  • Example 2: Frozen Core
  • Example 3: UHF Trial
  • Example 4: NOMSD Trial
  • Example 5: CASSCF Trial
  • Example 6: Back Propagation
  • Example 7: 2x2x2 Diamond supercell
  • Example 8: 2x2x2 Diamond k-point symmetry
• Additional Tools
  • Initialization
  • Postprocessing
  • Converters
  • Obtaining pseudopotentials
• External Tools
  • LLVM Sanitizer Libraries
  • Intel VTune
  • NVIDIA Tools Extensions
  • Scitools Understand
• Contributing to the Manual
• Unit Testing
  • Unit testing framework
  • Unit test organization
  • Example
  • Adding tests
  • Testing with random numbers
• QMCPACK Design and Feature Documentation
  • QMCPACK design
  • Feature: Optimized long-range breakup (Ewald)
  • Feature: Optimized long-range breakup (Ewald) 2
  • Feature: Cubic spline interpolation
  • Feature: B-spline orbital tiling (band unfolding)
  • Feature: Hybrid orbital representation
  • Feature: Electron-electron-ion Jastrow factor
  • Feature: Reciprocal-space Jastrow factors
• Development Guide
  • QMCPACK coding standards
  • Files
  • Naming
  • Comments
  • Formatting and “style”
  • QMCPACK C++ guidance
  • Scalar estimator implementation
  • Estimator output
  • Slater-backflow wavefunction implementation details
  • Particles and distance tables
  • Adding a wavefunction
  • Linear Algebra
• Appendices
  • Appendix A: Derivation of twist averaging efficiency

QMCPACK website: http://www.qmcpack.org

Releases & source code: https://github.com/QMCPACK

Google Group: https://groups.google.com/forum/#!forum/qmcpack