We are pleased to announce Questaal (https://www.questaal.org), the current CCP9 flagship (https://www.ccp9.ac.uk) supported by EPSRC. Questaal is an electronic structure package in an all-electron implementation. It has a variety of techniques based in density-functional theory, many body perturbation theory, and an interface to Haule’s implementation of dynamical mean field theory. A particular feature of the code is its implementation of the Quasiparticle Self-Consistent GW approximation (QSGW) which does not dependent on density-functional theory. Going beyond GW, ladder diagrams have been recently added to the GW package, to compute dielectric functions. The interface to Haule’s DMFT package can be enabled from QSGW or LDA inputs.
There is also an implementation of density functional theory in the Atomic Spheres Approximation, well suited to modeling spin transport in magnetic systems. There is a coherent potential approximation and a layer technique for computing transport in the Landauer-Buttiker or non-equilibrium framework.
The basis set consist of augmented smooth Hankel functions or a mix of them and Augmented Plane Waves (http://dx.doi.org/10.1103/PhysRevB.81.125117). A new “jigsaw puzzle orbital” basis set is nearly operational which should, by construction, be nearly optimal for a given rank of hamiltonian.
The Questaal web site documents many of the codes features, provides many tutorials, and explains how to download the code. For a quick test drive, you can also download precompiled binaries.