PRL Abstract
Abstract
In path integral molecular dynamics, efficient sampling of
the phase space is not guaranteed due to the stiff harmonic part of
the action arising from the quantum kinetic energy.
This problem has been eliminated by incorporating a sufficient
number of thermostats into the dynamical scheme and by introducing a
transformation of the path ``bead'' variables. In this paper, an efficient
Car-Parrinello path integral molecular dynamics algorithm, sufficiently
general to include the use of ultrasoft pseudopotentials is introduced.
Difficulties encountered when combining thermostats and
transformations of the cartesian ``bead'' coordinates with the generalized
orthonormality condition are circumvented
by employing a constrained nonorthogonal orbital method.