Transparent interface between classical molecular dynamics and first-principles molecular dynamics

A distinctive approach that combines first-principles Born-Oppenheimer local spin density molecular dynamics (BO-LSD-MD) with classical molecular dynamics is formulated, developed, and implemented to study silicon dioxide. Compared with previous hybrid schemes, our Hamiltonian is constructed to optimize the description of local chemistry in the center of the quantum region and mechanical properties at the quantum-classical boundary. With this method, the interface between the quantum and classical regions reflects faithfully the interatomic forces derived from quantum and classical descriptions, respectively. Ground-state structures obtained using our hybrid approach are compared with those calculated via quantum and classical methods. (C) 2003 Wiley Periodicals, Inc.