An efficient first-principle approach for electronic structures calculations of nanomaterials.

An efficient parallel implementation has been realized for a recently proposed central insertion scheme (Jiang, Liu, Lu, Luo. J Chem Phys 2006, 124, 214711; J Chem Phys 2006, 125, 149902) that allows to calculate electronic structures of nanomaterials at various density functional theory levels. It has adopted the sparse-matrix format for Fock/Kohn-Sham and overlap matrices, as well as a combination of implicitly restarted Arnoldi methods (IRAM) and spectral transformation for computing selected eigenvalues/eigenvectors. A systematic error analysis and control for the proposed method has been provided based on a strict mathematical basis. The efficiency and applicability of the new implementation have been demonstrated by calculations of electronic structures of two different nanomaterials consisting of one hundred thousand electrons. (c) 2007 Wiley Periodicals, Inc.