Electronic-structure theory, especially density-functional theory (DFT), is widely used in fields ranging from biophysics to materials science. Computer simulations are often the driving force behind innovative ways of molecular and materials’ design. Especially approaches based on the first principles of quantum mechanics provide an essentially unbiased understanding of molecules’ and materials’ properties and complement experimental techniques like scanning tunneling or atomic force microscopies, high-resolution photoemission spectroscopies, vibrational spectroscopies etc. While first-principles techniques are thus increasingly established and available by computer packages, it is critical to realize that the underlying methods are not trivial and offer a host of pitfalls for the unwary researcher. The most obvious pitfall, perhaps, is the apparent freedom of choice of the level of theory employed. This ranges from the choice of the functional or basis set to ways to account for relativity, magnetism, or long-range dispersion. Every method still gives a numerical result and it is up to the user to be able to judge whether it is physically meaningful. With the increase of computer power also advanced topics are now within reach for routine computation and need thus to be introduced to a broad audience:
- Excited-state properties via Green's function self-energy methods, e.g., the GW or the Bethe-Salpeter approximation,
- Free energies and thermodynamics of molecules and solids including anharmonic terms,
- Nuclear quantum effects can be modeled by specialized thermostats or by path-integral methods.
The creation of massive amounts of data for predicting materials with desired properties is becoming a more and more active field. In the organizers' experience, it is critical to teach these concepts in a personal and comprehensive way particularly for researchers entering the field. We here propose a ten-day “Hands-On” summer school on the basic numerical and physical concepts of first-principles computational methods based mostly on density-functional theory, but also on avenues “beyond”. The group in Berlin has a long-standing experience in organizing such schools dating back to 1994.