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.
An open-source program package for numerical diagonalization based on the Lanczos method, specialized for spin chains with unit spin magnitude, S=1. This package, which uses another open-source program package, TITPACK, calculates eigenenergies and eigenvectors of ground states and low-lying excited states of spin chains with finite length. By the subspace partitioning method, both memory and cpu-time requirements are considerably reduced.
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.
An application for structure prediction based on the evolutionary algorithm. From an input of the atomic position in a unit cell and possible elements at each atomic position, this application predicts the stable structure and composition from the first-principles calculation and molecular dynamics in combination with the evolutionary algorithm. This application is written in Python, and uses Quantum ESPRESSO and GULP as an external program.
An application for adding a function of the replica exchange method to the existing applications for molecular dynamics simulation such as MODYLAS, AMBER, and CHARMM. Without changing original programs of molecular dynamics, the replica exchange method can be implemented easily. This application also shows high performance in massive parallel computing by the K-computer.
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.
ALPS is a numerical simulation library for strongly correlated systems such as magnetic materials or correlated electrons. It contains typicalsolvers for strongly correlated systems: Monte Carlo methods, exact diagonalization, the density matrix renormalization group, etc. It can be used to calculate heat capacities, susceptibilities, magnetization processes in interacting spin systems, the density of states in strongly correlated electrons, etc. A highly efficient scheduler for parallel computing is another improvement.
※Related links are temporary changed due to the server maintenance for ALPS project.
Open-source tools and a database for molecular simulation. Data of molecular models (interatomic potentials and force fields), result data of molecular simulation, and test tools can be downloaded freely. API (Application Programming Interface) for exchanging information between atomistic simulation codes and interatomic models is also provided.
MODYLAS is a highly parallelized general-purpose molecular dynamics (MD) simulation program appropriate for very large physical, chemical, and biological systems. It is equipped most standard MD techniques including free energy calculations based on thermodynamic integration method. Long-range forces are evaluated rigorously by the fast multipole method (FMM) without using the fast Fourier transform (FFT) in order to realize excellent scalability. The program enables investigations of large-scale real systems such as viruses, liposomes, assemblies of proteins and micelles, and polymers. It works on ordinary linux machines, too.