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dc.contributor.authorYu, Li.en_US
dc.date.accessioned2009-06-04T14:09:18Z
dc.date.available2009-06-04T14:09:18Z
dc.date.issued2006-06-04T14:09:18Z
dc.identifier.urihttp://hdl.handle.net/10464/1529
dc.description.abstractWe examined three different algorithms used in diffusion Monte Carlo (DMC) to study their precisions and accuracies in predicting properties of isolated atoms, which are H atom ground state, Be atom ground state and H atom first excited state. All three algorithms — basic DMC, minimal stochastic reconfiguration DMC, and pure DMC, each with future-walking, are successfully impletmented in ground state energy and simple moments calculations with satisfactory results. Pure diffusion Monte Carlo with future-walking algorithm is proven to be the simplest approach with the least variance. Polarizabilities for Be atom ground state and H atom first excited state are not satisfactorily estimated in the infinitesimal differentiation approach. Likewise, an approach using the finite field approximation with an unperturbed wavefunction for the latter system also fails. However, accurate estimations for the a-polarizabilities are obtained by using wavefunctions that come from the time-independent perturbation theory. This suggests the flaw in our approach to polarizability estimation for these difficult cases rests with our having assumed the trial function is unaffected by infinitesimal perturbations in the Hamiltonian.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectMonte Carlo method.en_US
dc.subjectAlgorithms.en_US
dc.titleDiffusion Monte Carlo study of electronic properties for H and Be atoms /en_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.nameM.Sc. Physicsen_US
dc.degree.levelMastersen_US
dc.contributor.departmentDepartment of Physicsen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US


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