Fernanda Ferreira - Academia.edu (original) (raw)
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ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development
Université des Sciences et Technologies de Lille (Lille-1)
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Papers by Fernanda Ferreira
We introduce a method for the solution of the electronic-structure problem in the independentelec... more We introduce a method for the solution of the electronic-structure problem in the independentelectron approximation. The method is based upon a variational solution for the density matrix, which is truncated to zero beyond a real-space radius R"and becomes exact as R, -+~. Most importantly, the computer time scales only linearly with system size. The method is tested in the context of tight-binding models in one and three dimensions.
A transferable tight-binding model for silicon is found by fitting the energies of silicon in var... more A transferable tight-binding model for silicon is found by fitting the energies of silicon in various bulk crystal structures and examining functional parametrizations of the tight-binding forms. The model has short-range radial forms similar to the tight-binding Hamiltonian of Goodwin, Skinner, and Pettifor but can be utilized in molecular dynamics with a fixed radial cutoff for all structural configurations. In addition to a very good fit to the energy of Si in different bulk crystal structures the model describes very well the elastic constants, defect-formation energies for vacancies and interstitials in crystalline silicon, the melting of Si, and short-range order in liquid silicon. Results for phonon frequencies and Griineisen constants in c-Si are also presented.
We introduce a method for the solution of the electronic-structure problem in the independentelec... more We introduce a method for the solution of the electronic-structure problem in the independentelectron approximation. The method is based upon a variational solution for the density matrix, which is truncated to zero beyond a real-space radius R"and becomes exact as R, -+~. Most importantly, the computer time scales only linearly with system size. The method is tested in the context of tight-binding models in one and three dimensions.
A transferable tight-binding model for silicon is found by fitting the energies of silicon in var... more A transferable tight-binding model for silicon is found by fitting the energies of silicon in various bulk crystal structures and examining functional parametrizations of the tight-binding forms. The model has short-range radial forms similar to the tight-binding Hamiltonian of Goodwin, Skinner, and Pettifor but can be utilized in molecular dynamics with a fixed radial cutoff for all structural configurations. In addition to a very good fit to the energy of Si in different bulk crystal structures the model describes very well the elastic constants, defect-formation energies for vacancies and interstitials in crystalline silicon, the melting of Si, and short-range order in liquid silicon. Results for phonon frequencies and Griineisen constants in c-Si are also presented.