CyGutz

Abstract

This software is an efficient computational package of the Gutzwiller variational method. It solves the Gutzwiller variational problem for general multiband models with arbitrary on-site interaction in a fully self-consistent numerical approach. The underlying algorithm drastically reduces the problem of the high-dimensional Gutzwiller minimization by mapping it to a minimization only in the variational density matrix. For fixed density the Gutzwiller renormalization matrix is determined as a fix-point of a proper functional, whose evaluation requires only ground-state calculations of matrices defined in the Gutzwiller variational space. Furthermore, the package is able to account for the symmetries of the variational function in a controlled way, reducing the number of variational parameters. The software is highly efficient and robust, and is particularly suitable for first-principles studies (e.g., in combination with DFT) of many complex real materials, where the full intra-atomic interaction is important to obtain correct results.