DFTpy: An efficient and object-oriented platform for orbital-free DFT simulations

Abstract

In silico materials design is hampered by the computational complexity of Kohn-Sham DFT, which scales cubically with the system size. Owing to the development of new-generation kinetic energy density functionals (KEDFs), orbital-free DFT (OFDFT, a linear-scaling method) can now be successfully applied to a large class of semiconductors and such finite systems as quantum dots and metal clusters. In this work, we present DFTpy, an open source software implementing OFDFT written entirely in Python 3 and outsourcing the computationally expensive operations to third-party modules, such as NumPy and SciPy. When fast simulations are in order, DFTpy exploits the fast Fourier transforms (FFTs) from PyFFTW. New-generation, nonlocal and density-dependent-kernel KEDFs are made computationally efficient by employing linear splines and other methods for fast kernel builds. We showcase DFTpy by solving for the electronic structure of a million-atom system of aluminum metal which was computed on a single CPU. The Python 3 implementation is object-oriented, opening the door to easy implementation of new features. As an example, we present a time-dependent OFDFT implementation (hydrodynamic DFT) which we use to compute the spectra of small metal cluster recovering qualitatively the time-dependent Kohn-Sham DFT result. The Python code base allows for easy implementation of APIs. We showcase the combination of DFTpy and ASE for molecular dynamics simulations (NVT) of liquid metals. DFTpy is released under the MIT license.

References in corpus (17)

• Exact factorization of the time-dependent electron-nuclear wavefunction
• Quantum Hydrodynamic Theory for Plasmonics: Impact of the Electron Density Tail
• A Simple Generalized Gradient Approximation for the Non-interacting Kinetic Energy Density Functional
• Orbital-Free Density Functional Theory Implementation with the Projector Augmented-Wave Method
• Nonlocal Kinetic Energy Functionals By Functional Integration
• Subsystem Density-Functional Theory as an Effective Tool for Modeling Ground and Excited States, their Dynamics, and Many-Body Interactions
• Finite-temperature orbital-free DFT molecular dynamics: coupling Profess and Quantum Espresso
• Hydrodynamic theory of an electron gas
• ATLAS: A Real-Space Finite-Difference Implementation of Orbital-Free Density Functional Theory
• Orbital-Free DFT Correctly Models Quantum Dots When Asymptotics, Nonlocality and Nonhomogeneity Are Accounted For
• Exact single-electron approach to the dynamics of molecules in strong laser fields
• Non-local kinetic energy functional from the Jellium-with-gap model: applications to Orbital-Free Density Functional Theory
• Conjugate-Gradient Optimization Method for Orbital-free Density Functional Calculations
• Jellium-with-gap model applied to semilocal kinetic functionals
• Nonlocal Kinetic Energy Density Functionals for Isolated Systems via Local Density Approximation Kernels
• Fast method for force computations in electronic structure calculations
• A linear scaling method to evaluate the ion-electron potential of crystalline solids

Cited by in corpus (19)

• First principles simulations of dense hydrogen
• Roadmap on Nonlocality in Photonic Materials and Metamaterials
• Overcoming the Barrier of Orbital-Free Density Functional Theory for Molecular Systems Using Deep Learning
• Time-dependent Orbital-free Density Functional Theory: Background and Pauli kernel approximations
• Accelerating Equilibration in First-Principles Molecular Dynamics with Orbital-Free Density Functional Theory
• From Density Response to Energy Functionals and Back: An ab initio perspective on Matter Under Extreme Conditions
• An Efficient DFT Solver for Nanoscale Simulations and Beyond
• Automatic Differentiation for Orbital-Free Density Functional Theory
• Nonlocal and nonadiabatic Pauli potential for time-dependent orbital-free density functional theory
• Imposing Correct Jellium Response Is Key to Predict the Density Response by Orbital-Free DFT
• Robust All-Electron Optimization in Orbital-Free Density Functional Theory Using the Trust Region Image Method
• Coupled Maxwell and Time-Dependent Orbital Free Density Functional Calculations
• A machine-learned kinetic energy model for light weight metals and compounds of group III-V elements
• Nonlocal vs Local Pseudopotentials Affect Kinetic Energy Kernels in Orbital-Free DFT
• Efficient single-grid and multi-grid solvers for real-space orbital-free density functional theory
• Machine learning-guided construction of an analytic kinetic energy functional for orbital free density functional theory
• Generalized density functional theory framework for the non-linear density response of quantum many-body systems
• Nonlocal Orbital-Free Kinetic Energy Functional from the Jellium-with-Gap Model for Finite Systems
• Unlocking the Power of Orbital-Free Density Functional Theory to Explore the Electronic Structure Under Extreme Conditions