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.
An application for atomic multiplet calculation used in X-ray spectroscopies. This application consists of several calculation modules and graphical user interface, and can perform multiplet calculation of atoms. It can take into account effect of crystal fields and charge transfer, both of which are important in transition-metal compounds, and can provide useful information to interpret experimental results obtained in various inner-shell electron X-ray spectroscopies.
A C++ library for implementing a tensor product wavefunction method to simulate many-body electron systems. This library provides a useful environment for simple definition of tensors in programs, and supports functions of linear algebras and quantum number conservation needed in a tensor network method. This library keeps excellent flexibility and efficiency in maintenance, and can easily make a solver of one-dimensional electron systems such as density-matrix renormalization group (DMRG).
Library for calculating Pfaffian (square root of determinant), which is defined for skew-symmetric matrices. Algorithms are implemented in several languages (Fortran, Python, Matlab, Mathematica) and users can choose favorite one. Interfaces for C are also provided.
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.
Application for specifying and simulating lattice kinetic Monte Carlo models. It has been developed in the context of simulating heterogeneous catalysis. Models can be specified using provided python APIs or through a simple GUI.
A low-energy solver for a wide ranger of quantum lattice models (multi-orbital Hubbard model, Heisenberg model, Kondo-lattice model) by using variational Monte Carlo method. User can obtain high-accuracy wave functions for ground states of above models. Users flexibly choose the correlation factors in wavefunctions such as Gutzwiller, Jastrow, and doublon-holon binding factors and optimize more the ten thousand variational parameters. It is also possible to obtain the low-energy excited states by specifying the quantum number using the quantum number projection.
An open-source application for simulation of one-dimensional interacting electron models based on a tensor product wavefunction method. This application supports not only electronic models but also spin and bosonic models, and can evaluate various physical quantities for ground states and low-lying excited states. This application also supports time evolution, and can treat models with long-range interactions.
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.