AMULET is a collection of tools for a first principles calculation of physical properties of strongly correlated materials. It is based on density functional theory (DFT) combined with dynamical mean-field theory (DMFT). The later is the best local approximation for a solution of a strongly correlated problem and describes properly spin, orbital and charge degrees of freedom. Being a self-consistent time-dependent theory, DMFT treats on equal footing different energy scales that makes it applicable for an investigation of an entire phase diagram. The density functional theory is used to obtain a material specific part of the DFT+DMFT problem. The main code can perform the DFT+DMFT calculations with use of different solvers for an effective quantum impurity model. Different magnetic, electronic and structural properties can be evaluated in paramagnetic or magnetically ordered phases. The calculations of properties of chemically disordered compounds and alloys are possible within CPA+DMFT formalism. Different code features allow one to study spectral, magnetic or structural properties. At present, the code integrated with Quantum Espresso, ELK-code and Stuttgart's TB-LMTO.
Main features
AMULET can communicate with different band structure packages using a very simple tag-based format
At present, our implementation of interfaces for one of the most popular pseudopotential code, Quantum ESPRESSO, and plane wave based density functional package, ELK, allows one easy and simple DFT+DMFT calculations. The interface between AMULET and Wannier90 is ready, and thus, it drastically extends a number of band structure packages compatible with the AMULET. All band structure packages with Wannier90 interface, including VASP, can be used with the AMULET.
You can use different solvers for a solution of effective quantum impurity problem
A segment version of the continuous time quantum Monte Carlo is the best for compounds with a large orbital degeneracy and it can operate down to very low temperatures. But it is restricted to a density-density interacting part of Hamiltonian. The Hirsch-Fye quantum Monte Carlo works at relatively large temperatures but this solver can calculate off-diagonal Green functions and perfect for cluster DMFT calculations. The Hubbard I solver is well suited for the 4f electron systems to study atomic multiplet effects. It works down to extremely low temperatures and spin-orbit compatible.
Alloys with strong electron correlations are not a problem anymore!
Using a CPA+DMFT formalism realized in the AMULET package you can easily treat strongly correlated alloys with a substitutional type of disorder. Paramagnetic or magnetically ordered structures can be investigated. Different electronic, magnetic and structural properties can be evaluated as a function of temperature, concentration or other parameters and corresponding phase diagrams can be plotted.
AMULET is more than a code for DFT+DMFT calculations only
This is a collection of pre- and post- processing tools that can help you in analyzing band structure data and your DMFT results. Some of these routines can be utilized completely independently. For example, if you have the Hamiltonian in localized basis set and compatible with the AMULET format you can quickly obtain hopping integrals or evaluate exchange interaction parameters.