| 1 | /* | 
| 2 | * Copyright (c) 2005 The University of Notre Dame. All Rights Reserved. | 
| 3 | * | 
| 4 | * The University of Notre Dame grants you ("Licensee") a | 
| 5 | * non-exclusive, royalty free, license to use, modify and | 
| 6 | * redistribute this software in source and binary code form, provided | 
| 7 | * that the following conditions are met: | 
| 8 | * | 
| 9 | * 1. Acknowledgement of the program authors must be made in any | 
| 10 | *    publication of scientific results based in part on use of the | 
| 11 | *    program.  An acceptable form of acknowledgement is citation of | 
| 12 | *    the article in which the program was described (Matthew | 
| 13 | *    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher | 
| 14 | *    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented | 
| 15 | *    Parallel Simulation Engine for Molecular Dynamics," | 
| 16 | *    J. Comput. Chem. 26, pp. 252-271 (2005)) | 
| 17 | * | 
| 18 | * 2. Redistributions of source code must retain the above copyright | 
| 19 | *    notice, this list of conditions and the following disclaimer. | 
| 20 | * | 
| 21 | * 3. Redistributions in binary form must reproduce the above copyright | 
| 22 | *    notice, this list of conditions and the following disclaimer in the | 
| 23 | *    documentation and/or other materials provided with the | 
| 24 | *    distribution. | 
| 25 | * | 
| 26 | * This software is provided "AS IS," without a warranty of any | 
| 27 | * kind. All express or implied conditions, representations and | 
| 28 | * warranties, including any implied warranty of merchantability, | 
| 29 | * fitness for a particular purpose or non-infringement, are hereby | 
| 30 | * excluded.  The University of Notre Dame and its licensors shall not | 
| 31 | * be liable for any damages suffered by licensee as a result of | 
| 32 | * using, modifying or distributing the software or its | 
| 33 | * derivatives. In no event will the University of Notre Dame or its | 
| 34 | * licensors be liable for any lost revenue, profit or data, or for | 
| 35 | * direct, indirect, special, consequential, incidental or punitive | 
| 36 | * damages, however caused and regardless of the theory of liability, | 
| 37 | * arising out of the use of or inability to use software, even if the | 
| 38 | * University of Notre Dame has been advised of the possibility of | 
| 39 | * such damages. | 
| 40 | */ | 
| 41 |  | 
| 42 | #include "primitives/GhostBend.hpp" | 
| 43 | #include "primitives/DirectionalAtom.hpp" | 
| 44 | namespace oopse { | 
| 45 |  | 
| 46 | /**@todo still a lot left to improve*/ | 
| 47 | void GhostBend::calcForce(RealType& angle) { | 
| 48 | DirectionalAtom* ghostAtom = static_cast<DirectionalAtom*>(atom2_); | 
| 49 |  | 
| 50 | Vector3d pos1 = atom1_->getPos(); | 
| 51 | Vector3d pos2 = ghostAtom->getPos(); | 
| 52 |  | 
| 53 | Vector3d r12 = pos1 - pos2; | 
| 54 | RealType d12 = r12.length(); | 
| 55 |  | 
| 56 | RealType d12inv = 1.0 / d12; | 
| 57 |  | 
| 58 | Vector3d r32 = ghostAtom->getElectroFrame().getColumn(2); | 
| 59 | RealType d32 = r32.length(); | 
| 60 |  | 
| 61 | RealType d32inv = 1.0 / d32; | 
| 62 |  | 
| 63 | RealType cosTheta = dot(r12, r32) / (d12 * d32); | 
| 64 |  | 
| 65 | //check roundoff | 
| 66 | if (cosTheta > 1.0) { | 
| 67 | cosTheta = 1.0; | 
| 68 | } else if (cosTheta < -1.0) { | 
| 69 | cosTheta = -1.0; | 
| 70 | } | 
| 71 |  | 
| 72 | RealType theta = acos(cosTheta); | 
| 73 |  | 
| 74 | RealType firstDerivative; | 
| 75 |  | 
| 76 | bendType_->calcForce(theta, firstDerivative, potential_); | 
| 77 |  | 
| 78 | RealType sinTheta = sqrt(1.0 - cosTheta * cosTheta); | 
| 79 |  | 
| 80 | if (fabs(sinTheta) < 1.0E-12) { | 
| 81 | sinTheta = 1.0E-12; | 
| 82 | } | 
| 83 |  | 
| 84 | RealType commonFactor1 = -firstDerivative / sinTheta * d12inv; | 
| 85 | RealType commonFactor2 = -firstDerivative / sinTheta * d32inv; | 
| 86 |  | 
| 87 | Vector3d force1 = commonFactor1*(r12*(d12inv*cosTheta) - r32*d32inv); | 
| 88 | Vector3d force3 = commonFactor2*(r32*(d32inv*cosTheta) - r12*d12inv); | 
| 89 | atom1_->addFrc(force1); | 
| 90 | ghostAtom->addFrc(-force1); | 
| 91 | /**@todo test correctness */ | 
| 92 | ghostAtom->addTrq(cross(r32, force3) ); | 
| 93 |  | 
| 94 | angle = theta /M_PI * 180.0; | 
| 95 |  | 
| 96 | } | 
| 97 | } //end namespace oopse | 
| 98 |  |