The Kohn-Sham equation in first-principles density functional theory (DFT) calculations is a nonlinear eigenvalue problem. Solving the nonlinear eigenproblem is usually the most expensive part in DFT calculations. Sparse iterative diagonalization methods that compute explicit eigenvectors can quickly become prohibitive for large scale problems. The Chebyshevfiltered subspace iteration (CheFSI) ...

In this paper, the quantum chemistry calculations related to the structural parameter of the three anions and the resulting complexes with glycine and alanine have been performed. The calculations were carried out using the HF and DFT method and in the base series 6-31G *. Natural Transplantation Orbital (NBO), hybrid capacity for bindings and is obtained. The ratio of the internal electrons, V...

1,2,3- Tricyanoferrocene and 1,3-dibromo-2,4,5-tricyanoferrocene have been synthesized via metallation usage of dimethylmalononitrile (DMMN) as cyanating agent. They are the first compounds where three nitrile functions could be introduced into ferrocene sceleton. Further studies on electrophilic cyanation lithiated haloferrocenes [Fe(C5HmX4-mLi)(C5H5)] (X=Cl, Br; m=0–3) show formation complex ...

We present in this article a pseudopotential (PP) database for DFT calculations in the context of the SIESTA code [1-3]. Comprehensive optimized PPs in two formats (psf files and input files for ATM program) are provided for 20 chemical elements for LDA and GGA exchange-correlation potentials. Our data represents a validated database of PPs for SIESTA DFT calculations. Extensive transferability...

A laser vaporisation source and a time-of-flight mass spectrometer are used for the production and detection of TiArn Ž . clusters. Parallel, density functional theory DFT calculations assist in extracting the structures of the first members of the series. The mass spectrum is dominated by one intense line of TiAr , for which the DFT calculations predict a regular 6 octahedron. q 1999 Elsevier ...

We perform first-principles density-functional calculations to investigate the electronic and atomic structure and formation energies of native defects and selected impurities ~O, Si, and Mg! in InN. For p-type material, the nitrogen vacancy has the lowest formation energy. In n-type material all defect formation energies are high. We discuss the effect of the band-gap underestimate in density ...