; Jiang, Jun
; Liu, Kai
; Luo, Yi] Royal Inst Technol, Dept Theoret Chem, S-10691 Stockholm, Sweden
; [Gao, Bin
; Wu, Ziyu] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Jiang, Jun
; Lu, Wei] Chinese Acad Sci, Natl Lab Infrared Phys, Shanghai Inst Tech Phys, Beijing 100864, Peoples R China
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.