Density functional theory in terms of a legendre transformation for beginners. Journal of Molecular Structure: THEOCHEM, 768(1-3):163 - 173, 2006.Kutzelnigg, W (2006) J Mol Struct (Theochem) 768: pp. 163Kutzelnigg W (2006). J Mol Struct (Theochem) 768: 163...