Xavier Andrade will give a lunch group meeting from 1-2.30 at the Division
Room today.
Author: Xavier Andrade
Title: Modified Ehrenfest formalism: A new approach for large scale
ab-initio molecular dynamics
Abstract: A major drawback of traditional AIMD methods is the necessity to
enforce the orthogonalization of the wave-functions, which can become the
bottleneck for very large systems. Alternatively, one can handle the
electron-ion dynamics within the Ehrenfest scheme where no explicit
orthogonalization is necessary, however the time step is too small for
practical applications. Here we preserve the desirable properties of
Ehrenfest in a new scheme that allows for a considerable increase of the
time step while keeping the system close to the Born-Oppenheimer surface. We
show that the automatically enforced orthogonalization is of fundamental
importance for large systems because not only improves the scaling of the
approach with the system size but also allows for a very efficient
parallelization. In this work we provide the formal details of the new
method, describe its implementation and present some applications to some
test systems. Comparisons with the widely used Car-Parrinello molecular
dynamics method are made.
Show replies by date