Iterative fluctuation charge model: a new variable charge molecular dynamics method.
In molecular simulations, calculation of environmentally dependent atomic charges is still a demanding task. Empirical and semiempirical methods have been proposed and applied to a wide range of problems with different success. In this paper, a new scheme based on the concept of electronegativity equalization is presented and its advantages over several other methods are discussed. This method is an extension of the fluctuation charge model [S. W. Rick, S. J. Stuart, and B. J. Berne, J. Chem. Phys. 101, 6141 (1994)]. By allowing multiple electronic iterations at each nuclear step, the condition of electronegativity equalization can be satisfied to a selected precision. Molecular dynamics simulations using this new method, as well as several other methods, are performed on alpha quartz. Analysis of the simulated results shows that it is advantageous to use the iterative fluctuation charge model in several different situations.
Ma
Ying
Y
Interfacial Molecular Science Laboratory, Department of Materials Science and Engineering, Rutgers University, Piscataway, NJ 08854, USA.
Garofalini
Stephen H
SH