Approach to kinetic energy density functionals: Nonlocal terms with the structure of the von Weizsaecker functional
- Departamento de Fisica Fundamental, Universidad Nacional de Educacion a Distancia (UNED), Apartado 60.14, E-28080 Madrid (Spain)
We propose a kinetic energy density functional scheme with nonlocal terms based on the von Weizsaecker functional, instead of the more traditional approach where the nonlocal terms have the structure of the Thomas-Fermi functional. The proposed functionals recover the exact kinetic energy and reproduce the linear response function of homogeneous electron systems. In order to assess their quality, we have tested the total kinetic energies as well as the kinetic energy density for atoms. The results show that these nonlocal functionals give as good results as the most sophisticated functionals in the literature. The proposed scheme for constructing the functionals means a step ahead in the field of fully nonlocal kinetic energy functionals, because they are capable of giving better local behavior than the semilocal functionals, yielding at the same time accurate results for total kinetic energies. Moreover, the functionals enjoy the possibility of being evaluated as a single integral in momentum space if an adequate reference density is defined, and then quasilinear scaling for the computational cost can be achieved.
- OSTI ID:
- 21140475
- Journal Information:
- Physical Review. A, Vol. 77, Issue 2; Other Information: DOI: 10.1103/PhysRevA.77.022502; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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