TRIQS/CTHYB: A continuous-time quantum Monte Carlo hybridisation expansion solver for quantum impurity problems

Abstract

We present TRIQS/CTHYB, a state-of-the art open-source implementation of the continuous-time hybridisation expansion quantum impurity solver of the TRIQS package. This code is mainly designed to be used with the TRIQS library in order to solve the self-consistent quantum impurity problem in a multi-orbital dynamical mean field theory approach to strongly-correlated electrons, in particular in the context of realistic electronic structure calculations. It is implemented in C++ for efficiency and is provided with a high-level Python interface. The code ships with a new partitioning algorithm that divides the local Hilbert space without any user knowledge of the symmetries and quantum numbers of the Hamiltonian. Furthermore, we implement higher-order configuration moves and show that such moves are necessary to ensure ergodicity of the Monte Carlo in common Hamiltonians even without symmetry-breaking. Program summaryProgram title: TRIQS/CTHYBCatalogue identifier: AEYU_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEYU_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland.Licensing provisions: GNU General Public Licence (GPLv3)No. of lines in distributed program, including test data, etc.: 159,017No. of bytes in distributed program, including test data, etc.: 10,215,893Distribution format: tar.gzProgramming language: C++/Python.Computer: Any architecture with suitable compilers including PCs and clusters.Operating system: Unix, Linux, OSX.RAM: Highly problem-dependentClassification: 7.3, 4.4.External routines: TRIQS, cmake.Nature of problem: Accurate solvers for quantum impurity problems are needed in condensed matter theory.Solution method: We present an efficient C++/Python open-source implementation of a continuous-time hybridisation expansion solver.Running time: Tests take less than a minute. Otherwise it is highly problem dependent (from minutes to several days).