Introduction to Density Functionals

The many-electron wavefunction. .., rNapf) contains a great deal of 

While a function is a rule which assigns a number f x) to a number X, a functional is a rule which assigns a number F f to a function /. For example, is a functional of the trial wavefunction f, given 

The functional derivative SF/6n r) tells us how the functional F n changes under a small variation 6n r)  

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Libero J. Bartolotti and Ken Flurchick, An Introduction to Density Functional Theory. 

Bartolotti LJ, Flurchick K. An introduction to density functional theory. In Lipkowitz KB, Boyd DB, eds. Reviews in Computational Chemistry. Vol. 7. New York VCH, 1995 187-216. 

We are particularly grateful to Eric Short for a critical reading of Chapters 2 and 3, for the additional calculations contained in Chapters 5 and 10, and for the brief introduction to Density Functional Theory, which is inserted as an Appendix to Chapter 5. 

J. M. Seminario, An Introduction to Density Functional Theory in Chemistry, in Modem Density Functional Theory a Tool for Chemistry, edited by J. M. Seminario and P. Politzer (Elsevier Science, Amsterdam, 1995). 

A comprehensive overview of quantum mechanics is given by Cohen-Tannoudji et al. (1977), and another good book is by Levine (2000). A staple text on solid-state physics is by Ashcroft and Mermin (1976). A thorough introduction to density-functional theory is given by Parr and Yang (1989). Two good books to learn more about molecular dynamics simulations are by Allen and Tildesley (1987) and Frenkel and Smit (1996). To learn more about pseudopotential methods, two sources with which to begin are by Pickett (1989) and Bachelet et al. (1982). 

We also present a brief introduction to density functional theory (DFT). This is a newer method that is steadily gaining popularity. We do not develop DFT as extensively as conventional ab initio theory, in part because the latter is the rigorous implementation of our qualitative notions of structure and bonding. So, while DFT may in time become the computational method of choice, ab initio molecular orbital theory is a pedagogically more useful introduction to advanced molecular quantum mechanics. 

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