In this talk, I will start by giving a general introduction on density-functional theory (DFT) methods,1 and describe the basic approximations made in DFT and the different families of exchange and correlation functionals used in computational chemistry softwares. Then, I will present our recent work on the construction of new types of density functionals within DFT using finite uniform electron gases.[2–6]
In particular, I will show how one can construct a simple exchange functional by extending the well-know local-density approximation (LDA) to finite uniform electron gases.7 This new generalized local-density approximation (GLDA) functional uses only two quantities : the electron density Ï and the curvature of the Fermi hole α. This alternative “rung 2†functional (see Fig. 1) can be easily coupled with generalized-gradient approximation (GGA) functionals to form a new family of “rung 3†meta-GGA (MGGA) functionals that we have named factorizable MGGAs (FMGGAs).
[1] R. G. Parr and W. Yang, Density-functional theory of atoms and molecules (Oxford, Clarendon Press, 1989).
[2] P. F. Loos, C. J. Ball, and P. M. W. Gill, J. Chem. Phys. 140, 18A524 (2014).
[3] P. F. Loos, Phys. Rev. A 89, 052523 (2014).
[4] D. Agboola, A. L. Knol, P. M. W. Gill, and P. F. Loos, J. Chem. Phys. 143, 084114 (2015).
[5] P. F. Loos and P. M. W. Gill, WIREs Comput. Mol. Sci. 6, 410 (2016).
[6] F. J. M. Rogers, C. J. Ball, and P. F. Loos, Phys. Rev. B 93, 235114 (2016).
[7] P. F. Loos, J. Chem. Phys. (in press).
