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root/OpenMD/trunk/src/restraints/MolecularRestraint.cpp
Revision: 1360
Committed: Mon Sep 7 16:31:51 2009 UTC (15 years, 7 months ago) by cli2
File size: 7236 byte(s)
Log Message:
Added new restraint infrastructure
Added MolecularRestraints
Added ObjectRestraints
Added RestraintStamp
Updated thermodynamic integration to use ObjectRestraints
Added Quaternion mathematics for twist swing decompositions
Significantly updated RestWriter and RestReader to use dump-like files
Added selections for x, y, and z coordinates of atoms
Removed monolithic Restraints class
Fixed a few bugs in gradients of Euler angles in DirectionalAtom and RigidBody
Added some rotational capabilities to prinicpalAxisCalculator

File Contents

# Content
1 /*
2 * Copyright (c) 2009 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 "restraints/MolecularRestraint.hpp"
43 #include "math/SquareMatrix3.hpp"
44 #include "math/SVD.hpp"
45 #include <utility>
46
47 //using namespace JAMA;
48
49 namespace oopse {
50
51 void MolecularRestraint::calcForce(std::vector<Vector3d> struc,
52 Vector3d molCom){
53
54 assert(struc.size() == ref_.size());
55
56 std::vector<Vector3d>::iterator it;
57
58 // clear out initial values:
59 pot_ = 0.0;
60 for(it = forces_.begin(); it != forces_.end(); ++it)
61 (*it) = 0.0;
62
63
64 if (restType_ & rtDisplacement) {
65 Vector3d del = molCom - refCom_;
66
67 RealType r = del.length();
68 RealType p = 0.5 * kDisp_ * r * r;
69
70 pot_ += p;
71
72 restInfo_[rtDisplacement] = std::make_pair(r, p);
73
74 for(it = forces_.begin(); it != forces_.end(); ++it)
75 (*it) = -kDisp_ * del * scaleFactor_;
76 }
77
78 for(it = struc.begin(); it != struc.end(); ++it)
79 (*it) -= molCom;
80
81 // rtDisplacement = 1, so anything higher than that requires orientations:
82 if (restType_ > 1) {
83 Vector3d tBody(0.0);
84
85 Mat3x3d R(0.0);
86
87 for (int n = 0; n < struc.size(); n++){
88
89 /*
90 * correlation matrix R:
91 * R(i,j) = sum(over n): y(n,i) * x(n,j)
92 * where x(n) and y(n) are two vector sets
93 */
94
95 R += outProduct(struc[n], ref_[n]);
96 }
97
98 // SVD class uses dynamic matrices, so we must wrap the correlation
99 // matrix before calling SVD and then unwrap the results into Mat3x3d
100 // and Vector3d before we use them.
101
102 DynamicRectMatrix<RealType> Rtmp(3, 3, 0.0);
103 DynamicRectMatrix<RealType> vtmp(3, 3);
104 DynamicVector<RealType> stmp(3);
105 DynamicRectMatrix<RealType> wtmp(3, 3);
106
107 Rtmp.setSubMatrix(0, 0, R);
108
109 // Heavy lifting goes here:
110
111 JAMA::SVD<RealType> svd(Rtmp);
112
113 svd.getU(vtmp);
114 svd.getSingularValues(stmp);
115 svd.getV(wtmp);
116
117 Mat3x3d v;
118 Vector3d s;
119 Mat3x3d w_tr;
120
121 vtmp.getSubMatrix(0, 0, v);
122 stmp.getSubVector(0, s);
123 wtmp.getSubMatrix(0, 0, w_tr);
124
125 bool is_reflection = (v.determinant() * w_tr.determinant()) < 0.0;
126
127 if (is_reflection){
128 v(2, 0) = -v(2, 0);
129 v(2, 1) = -v(2, 1);
130 v(2, 2) = -v(2, 2);
131 }
132
133 RotMat3x3d Atrans = v * w_tr.transpose();
134 RotMat3x3d A = Atrans.transpose();
135
136 Vector3d eularAngles = A.toEulerAngles();
137
138
139 RealType twistAngle, swingAngle;
140 Vector3d swingAxis;
141
142 Quat4d quat = A.toQuaternion();
143
144 quat.getTwistSwingAxisAngle(twistAngle, swingAngle, swingAxis);
145
146 RealType tw, sx, sy, ttw, swingX, swingY;
147 quat.toTwistSwing(tw, sx, sy);
148 quat.toSwingTwist(swingX, swingY, ttw);
149
150 // std::cerr << eularAngles << "\t[" << twistAngle << "," << swingAngle <<
151 // "]\t[" << tw << "," << sx << "," << sy << "]\t[" << ttw <<
152 // "," << ssx << "," << ssy << "]" << std::endl;
153
154 RealType dVdtwist, dVdswing, dVdswingX, dVdswingY;
155 RealType dTwist, dSwing, dSwingX, dSwingY;
156 RealType p;
157
158 if (restType_ & rtTwist){
159 dTwist = twistAngle - twist0_;
160 dVdtwist = kTwist_ * sin(dTwist) ;
161 p = kTwist_ * (1.0 - cos(dTwist) ) ;
162 pot_ += p;
163 tBody -= dVdtwist * V3Z;
164 restInfo_[rtTwist] = std::make_pair(twistAngle, p);
165 }
166
167 // if (restType_ & rtSwing){
168 // dSwing = swingAngle - swing0_;
169 // dVdswing = kSwing_ * 2.0 * sin(2.0 * dSwing);
170 // p = kSwing_ * (1.0 - cos(2.0 * dSwing));
171 // pot_ += p;
172 // tBody -= dVdswing * swingAxis;
173 // restInfo_[rtSwing] = std::make_pair(swingAngle, p);
174 // }
175
176 if (restType_ & rtSwingX){
177 dSwingX = swingX - swingX0_;
178 dVdswingX = kSwingX_ * 2.0 * sin(2.0 * dSwingX);
179 p = kSwingX_ * (1.0 - cos(2.0 * dSwingX));
180 pot_ += p;
181 tBody -= dVdswingX * V3X;
182 restInfo_[rtSwingX] = std::make_pair(swingX, p);
183 }
184 if (restType_ & rtSwingY){
185 dSwingY = swingY - swingY0_;
186 dVdswingY = kSwingY_ * 2.0 * sin(2.0 * dSwingY);
187 p = kSwingY_ * (1.0 - cos(2.0 * dSwingY));
188 pot_ += p;
189 tBody -= dVdswingY * V3Y;
190 restInfo_[rtSwingY] = std::make_pair(swingY, p);
191 }
192
193
194 RealType t2 = dot(tBody, tBody);
195
196 Vector3d rLab, rBody, txr, fBody, fLab;
197
198 for (int i = 0; i < struc.size(); i++) {
199
200 rLab = struc[i];
201 rBody = A * rLab;
202
203 txr = cross(tBody, rBody);
204 fBody = txr * t2;
205 fLab = Atrans * fBody;
206 fLab *= scaleFactor_;
207
208 forces_[i] += fLab;
209 }
210
211 // test the force vectors and see if it is the right orientation
212 // std::cout << struc.size() << std::endl << std::endl;
213 // for (int i = 0; i != struc.size(); ++i){
214 // std::cout << "H\t" << struc[i].x() << "\t" << struc[i].y() << "\t" << struc[i].z() << "\t";
215 // std::cout << forces_[i].x() << "\t" << forces_[i].y() << "\t" << forces_[i].z() << std::endl;
216 // }
217 }
218 }
219 }