Title of Dissertation: PATH-INTEGRAL MONTE-CARLO SIMULATIONS OF ALUMINUM ATOMS EMBEDDED IN SOLID PARA-HYDROGEN AND IN HELIUM CLUSTERS Qian Wang, Doctor of Philosophy, 2005 Dissertation Directed By: Professor Millard H. Alexander Department of Chemistry and Biochemistry & The Institute for Physical Science and Technology, University of Maryland In this dissertation we use a path-integral Monte C...

A new embedded-atom method (EAM) potential has been constructed for Ag by fitting to experimental and first-principles data. The potential accurately reproduces the lattice parameter, cohesive energy, elastic constants, phonon frequencies, thermal expansion, lattice-defect energies, as well as energies of alternate structures of Ag. Combining this potential with an existing EAM potential for Cu...

Using the embedded atom model potential proposed for Ni-Al systems by Voter and Chen, we performed molecular-dynamics simulations to compute the quenched structures of small Nin clusters (n<10) deposited on or just beneath the Al ~001! surface. Embedded clusters were always more stable than adsorbed clusters. Determination of spin-polarized electronic structures using a self-consistent spd tigh...

OOPSE is a new molecular dynamics simulation program that is capable of efficiently integrating equations of motion for atom types with orientational degrees of freedom (e.g. "sticky" atoms and point dipoles). Transition metals can also be simulated using the embedded atom method (EAM) potential included in the code. Parallel simulations are carried out using the force-based decomposition metho...

We study atomistically the fracture of single-crystal silicon at atomically sharp notches with opening angles of 0° ~a crack!, 70.53°, 90° and 125.3°. Such notches occur in silicon that has been formed by etching into microelectromechanical structures and tend to be the initiation sites for failure by fracture of these structures. Analogous to the stress intensity factor of traditional linear e...