QuSpin is a python package for performing exact diagonalization and real- or imaginary-time evolution for quantum many-body systems. Using QuSpin, for example, it is possible to study the many-body localization and the quantum quenches in the Heisenberg chain. Moreover, QuSpin specifies the symmetries in the systems such as the total magnetization, the parity, the spin inversion, the translation symmetry, and their combinations.
RESPACK is a first-principles calculation software for evaluating the interaction parameters of materials. It is able to calculate the maximally localized Wannier functions, the RPA response functions, and frequency-dependent electronic interaction parameters. RESPACK receives its input data from a band calculation using norm-conserving pseudopotentials with plane-wave basis sets. Utilities which convert a result of xTAPP or Quantum ESPRESSO to an input for RESPACK are prepared. The software has been used successfully for a wide range of materials such as metals, semiconductors, transition-metal compounds, and organic compounds. It supports OpenMP / MPI parallelization.
A unified wrapper library for sequential and parallel versions of eigenvalue solvers. Sequential versions of dense-matrix diagonalization (LAPACK), parallel versions of dense-matrix diagonalization (EigenExa, ELPA, ScaLAPACK, etc.), and sequential/parallel versions of sparse-matrix diagonalization (SLEPc, Trilinos/Anasazi, etc.) can be installed quickly, and can be called from user’s program easily. Physical quantities written by eigenvalues or eigenvectors can also be evaluated by both sequential and parallel computation.
An open-source application for simulation of low-dimensional interacting electron models based on density-matrix renormalization group (DMRG). For effective models of one-dimensional quantum systems and impurity systems, this application can treat not only physical quantities of ground states but also time evolution and finite-temperature physical quantities. The program is coded in C++, and can be called from MATLAB scripts.
Server for computing exact ground state of Ising model with random interacitons (Ising spin glasses). Users can specify the distributions of the interactions and the geometry of lattices. By inputting the informaiont of the model, users will receive the computational results by e-mail from the server.
A free software library for numerical diagonalization of quantum spin systems. Although the programs are based on TITPACK, they have been completely rewritten in C/C++ and several extensions have been added. It can handle, for example, the Heisenberg model, the Hubbard model, and the t-J model. This library supports dimension reduction of matrices exploiting symmetries, and it can run in parallel computing environments.
A sparse-modeling tool for computing the spectral function from the imaginary-time Green function. It removes statistical errors in quantum Monte Carlo data, and performs a stable analytical continuation. The obtained spectral function fulfills the non-negativity and the sum rule. The computation is fast and free from tuning parameters.
An open-source program package for numerical diagonalization of quantum spin systems. The FORTRAN source programs are relatively simple and highly readable, and it can be applied to various quantum spin systems by modifying the main routine. Both the Lanczos and the inverse iteration methods are implemented for calculation of eigenvalues and eigenvectors, as well as correlation functions. Can be also used for diagonalization problems of general sparse matrices.
An open-source solver for the impurity problem based on the continuous-time quantum Monte Carlo method. Imaginary-time Green’s functions of the impurity Anderson model and the effective impurity model in the dynamical mean-field approximation can be calculated with high speed by using an efficient Monte Carlo algorithm. The main programs are written by C++, and can be called from Python scripts.
w2dynamics is a hybridization-expansion continuous-time (CT-HYB) quantum Monte Carlo package, developed jointly in Wien and Würzburg. Users can calculate local two- and four-pointfermionic Green’s functions of multi-orbital impurity models. This application also provides DMFT Python code and an interface to wannier90 generated Hamiltonians.