The development and expansion of Questaal Suite has been led by Mark van Schilfgaarde since its inception. During his time with Ole Anderson’s group at the Max Planck Institute for Solid State Institute (1987-1988), Mark implemented Ole’s new tight-binding formulation of the LMTO-ASA method. This code served as the foundation for the well known Stuttgart LMTO-ASA package, and for many descendants of it, including an ASA-GW code by Aryasetiawan, the original formulation of LDA+U, an early formulation of noncollinear magnetism and of linear response for spin waves, and a the first implementation of exact exchange.

There have been many contributors; a partial list is provided below.

Questaal Developers

Mark van Schilfgaarde (King’s College London, U.K.) Primary Developer

Michael Methfessel (IHP, Germany) Primary developer of the antecedent to the full-potential package.

Tight Binding

Tony Paxton (King’s College London, U.K.)
Original Developer of the tight-binding package; ASA Downfolding

Sasha Lozovoi

Dimitar Pashov (King’s College London, U.K.) Primary developer of the tight-binding package and the Jigsaw Puzzle Orbitals. Primary Questaal suite maintainer.


Takao Kotani (Tottori University, Japan) Primary developer of the GW package. Professor Kotani maintains his code at Both the one-body and the GW code were the same in 2007. They have diverged since then but have many similarities.

Sergei Faleev Primary developer of Quasiparticle Self-Consistency in GW, and nonequilibrium Keldysh transport.

Martin Lueders (Daresbury Labs) Primary developer of the MPI version of the QSGW codes

Brian Cunningham (Queen’s University Belfast, U.K.) Primary developer of ladder diagrams added to GW by Bethe-Salpeter.

Savio Laricchia (King’s College London, U.K.) Primary developer of implementation of phonons and the electron-phonon interaction into the GW package


Lorenzo Sponza (King’s College London, U.K.) Primary developer of a QSGW+DMFT implementation

Paolo Pisanti (King’s College London, U.K.) Primary developer of interface between this package and Rutger’s DMFT


Walter Lambrecht (Case Western Reserve, Ohio) Added several features to the ASA and full-potential codes, e.g. LDA+U and the optics packages.

Green Functions

Kiril Belashchenko (University of Nebraska) CPA, Spin-Orbit Coupling, in the Green’s function package

Derek Stewart Transmission in the Landauer-Buttiker formalism (layer Green’s function), maintainer of LMSuite website

Fully relativistic Dirac solver

Athanasios Chantis (Editor, Physical Review) Implementation of the fully relativistic Dirac equation into the ASA package, for studying transport

Alena Vishina (King’s College London, U.K.) Self-consistent fully relativistic Dirac equation; relativistic linear response

Magnetic response

Liqin Ke (Ames Lab, Iowa) magnetic linear response, magnetic symmetry, Empty sphere finder


Pooya Azarhoosh (King’s College London, U.K.) Additions to the optics packaged; involved in code dissemination and documentation

Ben Kaube


Lewis Christiansen (Imperial College London, U.K.) Primary developer of Questaal web site

Scott McKechnie (King’s College London, U.K.) Electric Fields for Spin orbit coupling; involved in redesign of input system and documentation

Gergely Kantor (King’s College London, U.K.) Primary developer of Questaal web site