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Orbital-Corrected Orbital-Free Density Functional Theory

Friday, August 3, 2007 - 11:30am - 12:00pm
EE/CS 3-180
Yan Wang (University of British Columbia)
Density functional theory (DFT) has been firmly established as one of the most widely used first-principles quantum mechanical methods in many fields. Each of the two ways of solving the DFT problem, i.e., the traditional orbital-based Kohn-Sham (KS) and the orbital-free (OF) [1] schemes, has its own strengths and weaknesses. We have developed a new implementation of DFT, namely orbital-corrected OF-DFT (OO-DFT) [2], which coalesces the advantages and avoids the drawbacks of OF-DFT and KS-DFT and allows systems within different chemical bonding environment to be studied at a much lower cost than the traditional self-consistent KS-DFT method. For the cubic-diamond Si and the face-centered-cubic Ag systems, OO-DFT accomplishes the accuracy comparable to fully self-consistent KS-DFT with at most two non-self-consistent iterations [2] via accurately evaluating the total electronic energy before reaching the full self-consistency [2-5]. Furthermore, OO-DFT can achieve linear scaling by employing currently available linear-scaling KS-DFT algorithms and may provide a powerful tool to treat large systems of thousands of atoms within different chemical bonding environment much more efficiently than other currently available linear-scaling DFT methods. Our work also provides a new impetus to further improve OF-DFT method currently available in the literature.

[1] Y. A. Wang and E. A. Carter, in Theoretical Methods in Condensed Phase Chemistry, edited by S. D. Schwartz (Kluwer, Dordrecht, 2000), p. 117.

[2] B. Zhou and Y. A. Wang, J. Chem. Phys. 124, 081107 (2006). (Communication)

[3] “An Accurate Total Energy Density Functional,” B. Zhou and Y. A. Wang, Int. J. Quantum Chem. (in press).

[4] “The Total Energy Evaluation in the Strutinsky Shell Correction Method,” B. Zhou and Y. A. Wang, J. Chem. Phys. (in press).

[5] “Accelerating the Convergence of the Total Energy Evaluation in Density Functional Theory Calculations,” B. Zhou and Y. A. Wang, J. Chem. Phys. (submitted).