(3.5.7) Grimme : The fact that semilocal DFAs yield an inconsistent or even unbound description of small van-der-Waals complexes was discovered in the mid-90s by Becke, Hobza, and Pulay. Noble gas dimers have been investigated several times as difficult cases for KS-DFT, with large errors and sometimes qualitatively wrong behaviour being found. However, this "DFT failure" is actually a failure of the usual semi-local approximations and not of the theory itself. Around the same time, Meijer and Sprik presented an analysis of the problem for the typical case of the benzene dimer and noted related errors in the computed lattice energy or mass density of molecular crystals. General claims that semilocal DFAs cannot describe nonlocal long-range correlation (London forces) were occasionally made, 382 but without further theoretical explanation -in particular, regarding the role of the correlation functional. Even as late as in 2002, the situation was not clear as indicated by a study of van Mourik and Gdanitz, which identified over-repulsive as well as over-binding functionals. For a more detailed historic account of the development of the dispersion problem in Kohn-Sham DFT, which cannot be solved simply by including nonlocal Fock exchange as is done in hybrid functionals; see ref. 384.