The WIEN2k package is a computer program

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 written in Fortran

Fortran

Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...

 which performs quantum mechanical calculations on periodic solids

Computational chemical methods in solid state physics

Computational chemical methods in solid-state physics follow the same approach as they do for molecules, but with two differences. First, the translational symmetry of the solid has to be utilised, and second, it is possible to use completely delocalised basis functions such as plane waves as an...

. It uses the full-potential (linearized) augmented plane-wave

Plane wave

In the physics of wave propagation, a plane wave is a constant-frequency wave whose wavefronts are infinite parallel planes of constant peak-to-peak amplitude normal to the phase velocity vector....

 and local-orbitals [FP-(L)APW+lo] basis set

Basis set (chemistry)

A basis set in chemistry is a set of functions used to create the molecular orbitals, which are expanded as a linear combination of such functions with the weights or coefficients to be determined. Usually these functions are atomic orbitals, in that they are centered on atoms. Otherwise, the...

 to solve the Kohn–Sham equations of density functional theory

Density functional theory

Density functional theory is a quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by...

.

WIEN2k was originally developed by Peter Blaha and Karlheinz Schwarz from the Institute of Materials Chemistry of the Vienna University of Technology

Vienna University of Technology

Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" , it currently has about 26,200 students , 8 faculties and about 4,000 staff members...

. The first public release of the code was done in 1990. Then, the next releases were WIEN93, WIEN97, and WIEN2k.