Fig. 2. Map showing the accessibility of different calculable material properties for a set of common computational methods. The methods include several flavours of density functional theory (DFT) which differ in the treatment of the quantum mechanical electron–electron interactions (e.g. local density approximation (LDA) and generalised gradient approximation (GGA)) as well as empirical tight-binding and many-body GW approaches. The circle size corresponds to the scaling of the computational effort with system size, the shading of the left semicircle represents the researcher effort required to use the method, and the shading of the right semicircle represents the reliability of the results from the method. Some properties are currently not calculable with GW theory for solids, and thus these circles are omitted.