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/* |
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* Copyright (c) 2005 The University of Notre Dame. All Rights Reserved. |
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* |
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* The University of Notre Dame grants you ("Licensee") a |
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* non-exclusive, royalty free, license to use, modify and |
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* redistribute this software in source and binary code form, provided |
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* that the following conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the |
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* distribution. |
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* |
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* This software is provided "AS IS," without a warranty of any |
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* kind. All express or implied conditions, representations and |
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* warranties, including any implied warranty of merchantability, |
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* fitness for a particular purpose or non-infringement, are hereby |
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* excluded. The University of Notre Dame and its licensors shall not |
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* be liable for any damages suffered by licensee as a result of |
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* using, modifying or distributing the software or its |
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* derivatives. In no event will the University of Notre Dame or its |
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* licensors be liable for any lost revenue, profit or data, or for |
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* direct, indirect, special, consequential, incidental or punitive |
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* damages, however caused and regardless of the theory of liability, |
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* arising out of the use of or inability to use software, even if the |
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* University of Notre Dame has been advised of the possibility of |
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* such damages. |
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* |
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* SUPPORT OPEN SCIENCE! If you use OpenMD or its source code in your |
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* research, please cite the appropriate papers when you publish your |
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* work. Good starting points are: |
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* |
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* [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005). |
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* [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006). |
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* [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008). |
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* [4] Kuang & Gezelter, J. Chem. Phys. 133, 164101 (2010). |
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* [5] Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011). |
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*/ |
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|
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/** |
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* @file Torsion.hpp |
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* @author tlin |
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* @date 11/01/2004 |
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* @version 1.0 |
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*/ |
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|
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#ifndef PRIMITIVES_TORSION_HPP |
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#define PRIMITIVES_TORSION_HPP |
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|
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#include "primitives/ShortRangeInteraction.hpp" |
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#include "primitives/Atom.hpp" |
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#include "types/TorsionType.hpp" |
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#include <limits> |
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|
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namespace OpenMD { |
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struct TorsionData { |
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RealType angle; |
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RealType potential; |
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}; |
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|
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struct TorsionDataSet { |
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RealType deltaV; |
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TorsionData prev; |
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TorsionData curr; |
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}; |
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|
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|
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/** |
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* @class Torsion Torsion.hpp "types/Torsion.hpp" |
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*/ |
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class Torsion : public ShortRangeInteraction { |
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public: |
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using ShortRangeInteraction::getValue; |
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using ShortRangeInteraction::getPrevValue; |
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|
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Torsion(Atom* atom1, Atom* atom2, Atom* atom3, Atom* atom4, TorsionType* tt); |
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virtual ~Torsion() {} |
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virtual void calcForce(RealType& angle, bool doParticlePot); |
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|
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RealType getValue(int snapshotNo) { |
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Vector3d pos1 = atoms_[0]->getPos(snapshotNo); |
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Vector3d pos2 = atoms_[1]->getPos(snapshotNo); |
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Vector3d pos3 = atoms_[2]->getPos(snapshotNo); |
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Vector3d pos4 = atoms_[3]->getPos(snapshotNo); |
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|
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Vector3d r21 = pos1 - pos2; |
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Vector3d r32 = pos2 - pos3; |
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Vector3d r43 = pos3 - pos4; |
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|
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// Calculate the cross products and distances |
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Vector3d A = cross(r21, r32); |
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RealType rA = A.length(); |
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Vector3d B = cross(r32, r43); |
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RealType rB = B.length(); |
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|
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/* |
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If either of the two cross product vectors is tiny, that means |
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the three atoms involved are colinear, and the torsion angle is |
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going to be undefined. The easiest check for this problem is |
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to use the product of the two lengths. |
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*/ |
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if (rA * rB < OpenMD::epsilon) return numeric_limits<double>::quiet_NaN(); |
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|
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A.normalize(); |
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B.normalize(); |
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|
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// Calculate the sin and cos |
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RealType cos_phi = dot(A, B) ; |
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if (cos_phi > 1.0) cos_phi = 1.0; |
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if (cos_phi < -1.0) cos_phi = -1.0; |
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return acos(cos_phi); |
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} |
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|
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|
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RealType getPotential() { |
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return potential_; |
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} |
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|
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Atom* getAtomA() { |
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return atoms_[0]; |
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} |
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|
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Atom* getAtomB() { |
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return atoms_[1]; |
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} |
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|
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Atom* getAtomC() { |
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return atoms_[2]; |
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} |
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|
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Atom* getAtomD() { |
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return atoms_[3]; |
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} |
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|
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TorsionType * getTorsionType() { |
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return torsionType_; |
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} |
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|
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virtual std::string getName() { return name_;} |
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/** Sets the name of this torsion for selections */ |
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virtual void setName(const std::string& name) { name_ = name;} |
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|
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void accept(BaseVisitor* v) { |
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v->visit(this); |
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} |
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|
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protected: |
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|
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TorsionType* torsionType_; |
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std::string name_; |
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|
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RealType potential_; |
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}; |
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|
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} |
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#endif //PRIMITIVES_TORSION_HPP |