TY - JOUR
T1 - Algorithms for the electronic and vibrational properties of nanocrystals
AU - Chelikowsky, James R.
AU - Zayak, Alexey T.
AU - Chan, T. L.
AU - Tiago, Murilo L.
AU - Zhou, Yunkai
AU - Saad, Yousef
PY - 2009
Y1 - 2009
N2 - Solving the electronic structure problem for nanoscale systems remains a computationally challenging problem. The numerous degrees of freedom, both electronic and nuclear, make the problem impossible to solve without some effective approximations. Here we illustrate some advances in algorithm developments to solve the Kohn-Sham eigenvalue problem, i.e. we solve the electronic structure problem within density functional theory using pseudopotentials expressed in real space. Our algorithms are based on a nonlinear Chebyshev filtered subspace iteration method, which avoids computing explicit eigenvectors except at the first self-consistent-field iteration. Our method may be viewed as an approach to solve the original nonlinear Kohn-Sham equation by a nonlinear subspace iteration technique, without emphasizing the intermediate linearized Kohn-Sham eigenvalue problems. Replacing the standard iterative diagonalization at each self-consistent-field iteration by a Chebyshev subspace filtering step results in a significant speed-up, often an order of magnitude or more, over methods based on standard diagonalization. We illustrate this method by predicting the electronic and vibrational states for silicon nanocrystals.
AB - Solving the electronic structure problem for nanoscale systems remains a computationally challenging problem. The numerous degrees of freedom, both electronic and nuclear, make the problem impossible to solve without some effective approximations. Here we illustrate some advances in algorithm developments to solve the Kohn-Sham eigenvalue problem, i.e. we solve the electronic structure problem within density functional theory using pseudopotentials expressed in real space. Our algorithms are based on a nonlinear Chebyshev filtered subspace iteration method, which avoids computing explicit eigenvectors except at the first self-consistent-field iteration. Our method may be viewed as an approach to solve the original nonlinear Kohn-Sham equation by a nonlinear subspace iteration technique, without emphasizing the intermediate linearized Kohn-Sham eigenvalue problems. Replacing the standard iterative diagonalization at each self-consistent-field iteration by a Chebyshev subspace filtering step results in a significant speed-up, often an order of magnitude or more, over methods based on standard diagonalization. We illustrate this method by predicting the electronic and vibrational states for silicon nanocrystals.
UR - http://www.scopus.com/inward/record.url?scp=63649089622&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=63649089622&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/21/6/064207
DO - 10.1088/0953-8984/21/6/064207
M3 - Article
C2 - 21715910
AN - SCOPUS:63649089622
SN - 0953-8984
VL - 21
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
IS - 6
M1 - 064207
ER -