Chebyshev filtered subspace iteration

Using Chebyshev-Filtered Subspace Iteration and Windowing Methods to Solve the Kohn-Sham Problem... 

Using Chebyshev-Filtered Subspace Iteration and Windowing Methods.. 

After initial testing on small systems, Chelikowsky s group extended their real-space code (now called PARSEC) for a wide range of challenging applications.The applications include quantum dots, semiconductors, nanowires, spin polarization, and molecular dynamics to determine photoelectron spectra, metal clusters, and time-dependent DFT (TDDFT) calculations for excited-state properties. PARSEC calculations have been performed on systems with more than 10,000 atoms. The PARSEC code does not utilize MG methods but rather employs Chebyshev-filtered subspace acceleration and other efficient techniques during the iterative solution process. When possible, symmetries may be exploited to reduce the numbers of atoms treated explicitly. 

The proposed method combines the outer SCF iteration and the inner iteration required for diagonalization at each SCF step into one nonlinear subspace iteration. In this approach an initial subspace is progressively refined by a low degree Chebyshev polynomials filtering. This means that each basis vector is processed... 

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