# # CDDL HEADER START # # The contents of this file are subject to the terms of the Common Development # and Distribution License Version 1.0 (the "License"). # # You can obtain a copy of the license at # http://www.opensource.org/licenses/CDDL-1.0. See the License for the # specific language governing permissions and limitations under the License. # # When distributing Covered Code, include this CDDL HEADER in each file and # include the License file in a prominent location with the name LICENSE.CDDL. # If applicable, add the following below this CDDL HEADER, with the fields # enclosed by brackets "[]" replaced with your own identifying information: # # Portions Copyright (c) [yyyy] [name of copyright owner]. All rights reserved. # # CDDL HEADER END # # # Copyright (c) 2012, Regents of the University of Minnesota. All rights reserved. # # Contributors: # Ryan S. Elliott # Ellad B. Tadmor # Valeriu Smirichinski # Amit Singh This directory (Three_Body_Stillinger_Weber_Si__MO_405512056662_002) contains the Stillinger-Weber potential Model based on the KIM Model Driver Three_Body_Stillinger_Weber. This Model implements the Stillinger-Weber potential for Si. The following files are in this directory: LICENSE.CDDL The Common Development and Distribution License (CDDL) Version 1.0 file Makefile makefile to compile and build the Model based on the specified KIM Model Driver README This file Three_Body_Stillinger_Weber_Si.params Parameters file providing the Stillinger-Weber parameters for Si This file must have the follwing format: Line 1: A Line 2: B Line 3: p Line 4: q Line 5: a Line 6: lambda Line 7: gamma Line 8: sigma in Angstrom Line 9: epsilon in ev Line 10: costheta_0 Any additional lines will be silently ignored. References: 1. F. H. Stillinger and T. A. Weber, "Computer simulation of local order in condensed phases of silicon", Phys. Rev. B, vol. 31, 5262-5271, 1985 2. Ellad B. Tadmor and Ronald E. Miller, Modeling Materials: Continuum, Atomistic and Multiscale Techniques, Cambridge University Press, 2011 Description: /******************************************************************************* * For three-body potential any potential energy function for N-particle system can be written in the * following form of two-body and three-body terms: F(1, 2, ...., N) = sum_{i; 1 <= i < j <= N} phi_two(r; r = r_ij) + sum_{i; 1 <= i \neq j < k <= N} phi_three(r_ij, r_ik, r_jk); * For Stillinger-Weber, two-body term phi_two is phi_two(r) = epsilon * f_2(r_cap; r_cap = r/sigma); where f_2 is f_2(r_cap) = A * ( B*r_cap^(-p) - r_cap^-q ) * exp(1/(r_cap - a)); when r_cap < a = 0 when r_cap >= a * and three-body term phi_three is phi_three(r_ij, r_ik, r_jk) = epsilon * f_3(r1_cap, r2_cap, r3_cap); where r1_cap = r_ij/sigma, r2_cap = r_ik/sigma, r3_cap = r_jk/sigma, and f_3(r1_cap, r2_cap, r3_cap) = lambda * (exp(gamma((1/(r1_cap - a)) + (1/(r2_cap - a))))) * (costheta_jik - costheta_0)^2; when r1_cap < a && r2_cap < a = 0; otherwise costheta_jik = (r_ij^2 + r_ik^2 - r_jk^2) / (2*r_ij*r_ik). *******************************************************************************/