Introduction
This Tutorial Review provides a concise introduction to some practical
aspects of running Kohn–Sham density functional theory (KS-DFT)
calculations. It is intended as a guide for non-experts, students,
occasional practitioners, or anyone that wants to start its own
adventures in the “zoo” of DFT approximations. It is organized in
three parts. In the first part, we answer a few questions to establish a
necessary (but far from sufficient) foundation. In the second part, we
concentrate on the methodological components and we introduce the
discussion on the choice of the functional and basis set. In the third
part, we deal with some technical issues that are important for the
reliability and reproducibility of calculations. The purpose of this
tutorial is to draw awareness to the details, rather than being a
comprehensive guide for all DFT-related answers. To this extent, it
represents a complementary tutorial to other that have appeared in this
series, in particular to the foundational essay by K. Burke and L. O.
Wagner entitled “DFT in a Nutshell”.1 Because of its
general audience, the technical details of the reported issues have been
simplified to some degree. To make up for it, we provide a broad body of
references where the interested readers can find the important
technicalities of each discussed topic. This review is also accompanied
by a notebook of 12 calculation experiences, which is formatted for
students of an advanced undergraduate or graduate course, but it is
challenging enough to be interesting for more experienced users as well.