Bond-order potential for silicon

Abstract

The tight-binding description of covalent bonding is used to propose a four-level, bond-order potential for elemental silicon. The potential addresses both the and bonding and the valence of this sp-valent element. The interatomic potential is parametrized using ab initio and experimental data for the diamond cubic, simple cubic, face-centered-cubic, and body-centered-cubic phases of silicon. The bond-order potential for silicon is assessed by comparing the predicted values with other estimates of the cohesive energy, atomic volume, and bulk modulus for the ␤-Sn, bc8, st12, and 46 clathrate structures. The potential predicts a melting temperature of 1650± 50 K in good agreement with the experimental value of 1687 K. The energetics of various highsymmetry point defect structures and the structure and energetics of small silicon clusters are investigated. The potential also provides a robust description of surface reconstructions; it notably predicts with high fidelity the surface formation energy of the ͑111͒ 7 ϫ 7 dimer adatom stacking fault configuration.

Amorphous silicon under mechanical shear deformations: Shear velocity and temperature effects

“…The structural and dynamical properties of amorphous silicon (a-Si) have been extensively investigated using classical force fields [1][2][3][4][5][6][7][8][9][10][11][12] , tight-binding [15][16][17][18] and ab-initio simulations 13,14,19 . Much attention, in particular, has been devoted to the characterization of defects 12,[20][21][22][23][24][25][26][27][28][29][30][31] .…”

Atomistic examinations of the solid-phase epitaxial growth of silicon

“…A small secondary peak is also evident at a bond angle of 501. We note that a [11 0]-split type interstitial defect has a bond angle of 501, while a tetrahedral defect has bonds with an angle of 701 [17]. The average coordination of these interstitials was obtained by visually identifying 100 interstitial atoms in the various simulations and determining their coordinations.…”

“…[17][18][19][20][21]. There are numerous ways to synthesize amorphous silicon including quenching from the melt [22], low-temperature vapor deposition [23][24][25], and ion bombardment [26,27].…”

“…It also explicitly includes a term to account for the promotion energy associated with the hybridization of the atomic orbitals. While the BOP approach to molecular dynamics simulations is more computationally demanding than many other potentials, the use of this potential here is motivated by the high quality of its predictive results for silicon bulk properties (such as melting temperature and the cohesive energies of a wide range of structures) and its reasonable estimates for point defect energies and structures [17].…”

“…Here, we use a recently developed bond order potential (BOP) for silicon and a molecular dynamics simulation method to examine the initial stages of the amorphous to crystalline transformation of silicon [17][18][19][20][21]. The BOP is an analytic, manybody interatomic potential derived by coarse graining the electronic structure within a two-center, tight-binding representation of covalent bonding.…”