An open source library for implementing tensor networks. It is developed based on TensorFlow and is designed to be easily used by experts in the field of machine learning as well as in the field of physics. In addition to TensorFlow, it includes wrappers for JAX, PyTorch, and Numpy.
A set of tools for alloy theory analysis in combination with first-principles calculation packages. Free energy and thermodynamic phase diagrams of alloy systems are calculated by combining the cluster expansion method with Monte Carlo simulations. Interfaces with major first-principles code including Quantum Espresso, VASP, and ABINIT are provided.
Software tool for constructing interatomic potentials based on nonlinear atomic cluster expansion. It requires the user to either prepare a fitting dataset based on pandas and ASE, or it can automatically extract data from VASP calculation results. The obtained potentials can be used for molecular dynamics simulations using LAMMPS, and it also provides the capability to calculate extrapolation grades for on-the-fly active learning.
A collection of C++ interfaces for simulation of mesoscale properties based on grid data. By using provided header files, one can easily construct programs for simulation of various phenomena such as solidification, crystal growth, and spinodal decomposition, based on a Monte Carlo method, cellar automaton, and a phase-field method. This interface supports parallel computing by MPI, and also provides converters of output files for visualization software such as ParaView.
peps-torch is a python library for calculation of quantum many-body problems on two dimensional lattices. Variational principles calculation is used with an infinite PEPS (iPEPS) as the trial wave function. Therefore, the ground state is obtained in the form of the element tensor of the iPEPS. The energy of the trial state is estimated by the corner transfer matrix method (CTM), and its gradient with respect to the element tensor is computed through automatic differentiation provided by pytorch. Functions/classes for exploiting the system’s symmetry are provided for reducing the computational cost if possible. While general models and lattices are not supported, many examples of stand-alone codes would make it relatively easy for users to write their own codes to suit their needs. pytorch is required.
An application for prediction of stable and metastable structures from a chemical composition. This application applies particle swarm optimization to predict material structures from results of the first-principles calculation by external packages (VASP, CASTEP, Quantum Espresso, GULP, SIESTA, CP2k). It has been applied to predict not only three-dimensional crystal structures, but also those of clusters and surfaces.
A database for thermodynamic properties and crystal structures calculated based on the density functional theory by a research group in Northwestern University. OQMD provides over one million data generated by using not only experimental crystal structures provided by ICSD but also those obtained by calculations. Users can search data in OQMD by using Python API.
CCCM is a high-order CCM (coupled cluster method) code for lattice spin systems. It is possible to obtain the ground state and its energy of quantum spin systems in two or three dimensions.
This software is for constructing inter-atomic force fields that mostly fit the results of ab-initio calculations, using multi-canonical molecular dynamic simulations. Various potential functions such as silicon, ionic crystal, and water have been pre-installed, and the user’s potential function can also be used. The default ab initio calculation solver is xTAPP and other calculation libraries are also applicable.
QDS (Quantum Dynamics Simulator) is a program for computing magnetization curves and spectra of electron-spin resonance (ESR) in molecular magnets. Input data of this program can be magnetic interactions, the shape of a molecule, etc. Calculation is carried out with the combination of exact diagonalization, the quantum master equation, and the Kubo formula. It can be chosen whether the dissipation exists or not in the calculations of dynamical magnetization curves.