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root/OpenMD/branches/development/src/nonbonded/EAM.cpp
Revision: 1665
Committed: Tue Nov 22 20:38:56 2011 UTC (13 years, 5 months ago) by gezelter
File size: 15892 byte(s)
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# Content
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. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the
15 * distribution.
16 *
17 * This software is provided "AS IS," without a warranty of any
18 * kind. All express or implied conditions, representations and
19 * warranties, including any implied warranty of merchantability,
20 * fitness for a particular purpose or non-infringement, are hereby
21 * excluded. The University of Notre Dame and its licensors shall not
22 * be liable for any damages suffered by licensee as a result of
23 * using, modifying or distributing the software or its
24 * derivatives. In no event will the University of Notre Dame or its
25 * licensors be liable for any lost revenue, profit or data, or for
26 * direct, indirect, special, consequential, incidental or punitive
27 * damages, however caused and regardless of the theory of liability,
28 * arising out of the use of or inability to use software, even if the
29 * University of Notre Dame has been advised of the possibility of
30 * such damages.
31 *
32 * SUPPORT OPEN SCIENCE! If you use OpenMD or its source code in your
33 * research, please cite the appropriate papers when you publish your
34 * work. Good starting points are:
35 *
36 * [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).
37 * [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).
38 * [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).
39 * [4] Kuang & Gezelter, J. Chem. Phys. 133, 164101 (2010).
40 * [5] Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
41 */
42
43 #include <stdio.h>
44 #include <string.h>
45
46 #include <cmath>
47 #include "nonbonded/EAM.hpp"
48 #include "utils/simError.h"
49 #include "types/NonBondedInteractionType.hpp"
50
51
52 namespace OpenMD {
53
54 EAM::EAM() : name_("EAM"), initialized_(false), forceField_(NULL),
55 mixMeth_(eamJohnson), eamRcut_(0.0), haveCutoffRadius_(false) {}
56
57 EAMParam EAM::getEAMParam(AtomType* atomType) {
58
59 // Do sanity checking on the AtomType we were passed before
60 // building any data structures:
61 if (!atomType->isEAM()) {
62 sprintf( painCave.errMsg,
63 "EAM::getEAMParam was passed an atomType (%s) that does not\n"
64 "\tappear to be an embedded atom method (EAM) atom.\n",
65 atomType->getName().c_str());
66 painCave.severity = OPENMD_ERROR;
67 painCave.isFatal = 1;
68 simError();
69 }
70
71 GenericData* data = atomType->getPropertyByName("EAM");
72 if (data == NULL) {
73 sprintf( painCave.errMsg, "EAM::getEAMParam could not find EAM\n"
74 "\tparameters for atomType %s.\n",
75 atomType->getName().c_str());
76 painCave.severity = OPENMD_ERROR;
77 painCave.isFatal = 1;
78 simError();
79 }
80
81 EAMParamGenericData* eamData = dynamic_cast<EAMParamGenericData*>(data);
82 if (eamData == NULL) {
83 sprintf( painCave.errMsg,
84 "EAM::getEAMParam could not convert GenericData to EAMParam for\n"
85 "\tatom type %s\n", atomType->getName().c_str());
86 painCave.severity = OPENMD_ERROR;
87 painCave.isFatal = 1;
88 simError();
89 }
90
91 return eamData->getData();
92 }
93
94 CubicSpline* EAM::getZ(AtomType* atomType) {
95 EAMParam eamParam = getEAMParam(atomType);
96 int nr = eamParam.nr;
97 RealType dr = eamParam.dr;
98 vector<RealType> rvals;
99
100 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i) * dr);
101
102 CubicSpline* cs = new CubicSpline();
103 cs->addPoints(rvals, eamParam.Z);
104 return cs;
105 }
106
107 RealType EAM::getRcut(AtomType* atomType) {
108 EAMParam eamParam = getEAMParam(atomType);
109 return eamParam.rcut;
110 }
111
112 CubicSpline* EAM::getRho(AtomType* atomType) {
113 EAMParam eamParam = getEAMParam(atomType);
114 int nr = eamParam.nr;
115 RealType dr = eamParam.dr;
116 vector<RealType> rvals;
117
118 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i) * dr);
119
120 CubicSpline* cs = new CubicSpline();
121 cs->addPoints(rvals, eamParam.rho);
122 return cs;
123 }
124
125 CubicSpline* EAM::getF(AtomType* atomType) {
126 EAMParam eamParam = getEAMParam(atomType);
127 int nrho = eamParam.nrho;
128 RealType drho = eamParam.drho;
129 vector<RealType> rhovals;
130 vector<RealType> scaledF;
131
132 for (int i = 0; i < nrho; i++) {
133 rhovals.push_back(RealType(i) * drho);
134 scaledF.push_back( eamParam.F[i] * 23.06054 );
135 }
136
137 CubicSpline* cs = new CubicSpline();
138 cs->addPoints(rhovals, scaledF);
139 return cs;
140 }
141
142 CubicSpline* EAM::getPhi(AtomType* atomType1, AtomType* atomType2) {
143 EAMParam eamParam1 = getEAMParam(atomType1);
144 EAMParam eamParam2 = getEAMParam(atomType2);
145 CubicSpline* z1 = getZ(atomType1);
146 CubicSpline* z2 = getZ(atomType2);
147
148 // make the r grid:
149
150
151 // we need phi out to the largest value we'll encounter in the radial space;
152
153 RealType rmax = 0.0;
154 rmax = max(rmax, eamParam1.rcut);
155 rmax = max(rmax, eamParam1.nr * eamParam1.dr);
156
157 rmax = max(rmax, eamParam2.rcut);
158 rmax = max(rmax, eamParam2.nr * eamParam2.dr);
159
160 // use the smallest dr (finest grid) to build our grid:
161
162 RealType dr = min(eamParam1.dr, eamParam2.dr);
163
164 int nr = int(rmax/dr + 0.5);
165
166 vector<RealType> rvals;
167 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i*dr));
168
169 // construct the pair potential:
170
171 vector<RealType> phivals;
172 RealType phi;
173 RealType r;
174 RealType zi, zj;
175
176 phivals.push_back(0.0);
177
178 for (int i = 1; i < rvals.size(); i++ ) {
179 r = rvals[i];
180
181 // only use z(r) if we're inside this atom's cutoff radius,
182 // otherwise, we'll use zero for the charge. This effectively
183 // means that our phi grid goes out beyond the cutoff of the
184 // pair potential
185
186 zi = r <= eamParam1.rcut ? z1->getValueAt(r) : 0.0;
187 zj = r <= eamParam2.rcut ? z2->getValueAt(r) : 0.0;
188
189 phi = 331.999296 * (zi * zj) / r;
190
191 phivals.push_back(phi);
192 }
193
194 CubicSpline* cs = new CubicSpline();
195 cs->addPoints(rvals, phivals);
196 return cs;
197 }
198
199 void EAM::setCutoffRadius( RealType rCut ) {
200 eamRcut_ = rCut;
201 haveCutoffRadius_ = true;
202 }
203
204 void EAM::initialize() {
205
206 // set up the mixing method:
207 ForceFieldOptions& fopts = forceField_->getForceFieldOptions();
208 string EAMMixMeth = fopts.getEAMMixingMethod();
209 toUpper(EAMMixMeth);
210
211 if (EAMMixMeth == "JOHNSON")
212 mixMeth_ = eamJohnson;
213 else if (EAMMixMeth == "DAW")
214 mixMeth_ = eamDaw;
215 else
216 mixMeth_ = eamUnknown;
217
218 // find all of the EAM atom Types:
219 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
220 ForceField::AtomTypeContainer::MapTypeIterator i;
221 AtomType* at;
222
223 for (at = atomTypes->beginType(i); at != NULL;
224 at = atomTypes->nextType(i)) {
225
226 if (at->isEAM())
227 addType(at);
228 }
229
230 // find all of the explicit EAM interactions (setfl):
231 ForceField::NonBondedInteractionTypeContainer* nbiTypes = forceField_->getNonBondedInteractionTypes();
232 ForceField::NonBondedInteractionTypeContainer::MapTypeIterator j;
233 NonBondedInteractionType* nbt;
234
235 for (nbt = nbiTypes->beginType(j); nbt != NULL;
236 nbt = nbiTypes->nextType(j)) {
237
238 if (nbt->isEAM()) {
239
240 pair<AtomType*, AtomType*> atypes = nbt->getAtomTypes();
241
242 GenericData* data = nbt->getPropertyByName("EAM");
243 if (data == NULL) {
244 sprintf( painCave.errMsg, "EAM::rebuildMixingMap could not find\n"
245 "\tEAM parameters for %s - %s interaction.\n",
246 atypes.first->getName().c_str(),
247 atypes.second->getName().c_str());
248 painCave.severity = OPENMD_ERROR;
249 painCave.isFatal = 1;
250 simError();
251 }
252
253 EAMMixingData* eamData = dynamic_cast<EAMMixingData*>(data);
254 if (eamData == NULL) {
255 sprintf( painCave.errMsg,
256 "EAM::rebuildMixingMap could not convert GenericData to\n"
257 "\tEAMMixingData for %s - %s interaction.\n",
258 atypes.first->getName().c_str(),
259 atypes.second->getName().c_str());
260 painCave.severity = OPENMD_ERROR;
261 painCave.isFatal = 1;
262 simError();
263 }
264
265 EAMMixingParam eamParam = eamData->getData();
266
267 vector<RealType> phiAB = eamParam.phi;
268 RealType dr = eamParam.dr;
269 int nr = eamParam.nr;
270
271 addExplicitInteraction(atypes.first, atypes.second, dr, nr, phiAB);
272 }
273 }
274 initialized_ = true;
275 }
276
277
278
279 void EAM::addType(AtomType* atomType){
280
281 EAMAtomData eamAtomData;
282
283 eamAtomData.rho = getRho(atomType);
284 eamAtomData.F = getF(atomType);
285 eamAtomData.Z = getZ(atomType);
286 eamAtomData.rcut = getRcut(atomType);
287
288 // add it to the map:
289 AtomTypeProperties atp = atomType->getATP();
290
291 pair<map<int,AtomType*>::iterator,bool> ret;
292 ret = EAMlist.insert( pair<int, AtomType*>(atp.ident, atomType) );
293 if (ret.second == false) {
294 sprintf( painCave.errMsg,
295 "EAM already had a previous entry with ident %d\n",
296 atp.ident);
297 painCave.severity = OPENMD_INFO;
298 painCave.isFatal = 0;
299 simError();
300 }
301
302 EAMMap[atomType] = eamAtomData;
303
304 // Now, iterate over all known types and add to the mixing map:
305
306 map<AtomType*, EAMAtomData>::iterator it;
307 for( it = EAMMap.begin(); it != EAMMap.end(); ++it) {
308
309 AtomType* atype2 = (*it).first;
310
311 EAMInteractionData mixer;
312 mixer.phi = getPhi(atomType, atype2);
313 mixer.explicitlySet = false;
314
315 pair<AtomType*, AtomType*> key1, key2;
316 key1 = make_pair(atomType, atype2);
317 key2 = make_pair(atype2, atomType);
318
319 MixingMap[key1] = mixer;
320 if (key2 != key1) {
321 MixingMap[key2] = mixer;
322 }
323 }
324 return;
325 }
326
327 void EAM::addExplicitInteraction(AtomType* atype1, AtomType* atype2,
328 RealType dr, int nr,
329 vector<RealType> phiVals) {
330
331 // in case these weren't already in the map
332 addType(atype1);
333 addType(atype2);
334
335 EAMInteractionData mixer;
336 CubicSpline* cs = new CubicSpline();
337 vector<RealType> rVals;
338
339 for (int i = 0; i < nr; i++) rVals.push_back(i * dr);
340
341 cs->addPoints(rVals, phiVals);
342 mixer.phi = cs;
343 mixer.explicitlySet = true;
344
345 pair<AtomType*, AtomType*> key1, key2;
346 key1 = make_pair(atype1, atype2);
347 key2 = make_pair(atype2, atype1);
348
349 MixingMap[key1] = mixer;
350 if (key2 != key1) {
351 MixingMap[key2] = mixer;
352 }
353 return;
354 }
355
356 void EAM::calcDensity(InteractionData &idat) {
357
358 if (!initialized_) initialize();
359
360 EAMAtomData data1 = EAMMap[idat.atypes.first];
361 EAMAtomData data2 = EAMMap[idat.atypes.second];
362
363 if (haveCutoffRadius_)
364 if ( *(idat.rij) > eamRcut_) return;
365
366 if ( *(idat.rij) < data1.rcut)
367 *(idat.rho1) += data1.rho->getValueAt( *(idat.rij));
368
369
370 if ( *(idat.rij) < data2.rcut)
371 *(idat.rho2) += data2.rho->getValueAt( *(idat.rij));
372
373 return;
374 }
375
376 void EAM::calcFunctional(SelfData &sdat) {
377
378 if (!initialized_) initialize();
379
380 EAMAtomData data1 = EAMMap[ sdat.atype ];
381
382 pair<RealType, RealType> result = data1.F->getValueAndDerivativeAt( *(sdat.rho) );
383
384 *(sdat.frho) = result.first;
385 *(sdat.dfrhodrho) = result.second;
386
387 (*(sdat.pot))[METALLIC_FAMILY] += result.first;
388 *(sdat.particlePot) += result.first;
389
390 return;
391 }
392
393
394 void EAM::calcForce(InteractionData &idat) {
395
396 if (!initialized_) initialize();
397
398 if (haveCutoffRadius_)
399 if ( *(idat.rij) > eamRcut_) return;
400
401 pair<RealType, RealType> res;
402
403 EAMAtomData data1 = EAMMap[idat.atypes.first];
404 EAMAtomData data2 = EAMMap[idat.atypes.second];
405
406 // get type-specific cutoff radii
407
408 RealType rci = data1.rcut;
409 RealType rcj = data2.rcut;
410
411 RealType rha(0.0), drha(0.0), rhb(0.0), drhb(0.0);
412 RealType pha(0.0), dpha(0.0), phb(0.0), dphb(0.0);
413 RealType phab(0.0), dvpdr(0.0);
414 RealType drhoidr, drhojdr, dudr;
415
416 if ( *(idat.rij) < rci) {
417 res = data1.rho->getValueAndDerivativeAt( *(idat.rij));
418 rha = res.first;
419 drha = res.second;
420
421 res = MixingMap[make_pair(idat.atypes.first, idat.atypes.first)].phi->getValueAndDerivativeAt( *(idat.rij) );
422 pha = res.first;
423 dpha = res.second;
424 }
425
426 if ( *(idat.rij) < rcj) {
427 res = data2.rho->getValueAndDerivativeAt( *(idat.rij) );
428 rhb = res.first;
429 drhb = res.second;
430
431 res = MixingMap[make_pair(idat.atypes.second, idat.atypes.second)].phi->getValueAndDerivativeAt( *(idat.rij) );
432 phb = res.first;
433 dphb = res.second;
434 }
435
436 switch(mixMeth_) {
437 case eamJohnson:
438
439 if ( *(idat.rij) < rci) {
440 phab = phab + 0.5 * (rhb / rha) * pha;
441 dvpdr = dvpdr + 0.5*((rhb/rha)*dpha +
442 pha*((drhb/rha) - (rhb*drha/rha/rha)));
443 }
444
445
446
447 if ( *(idat.rij) < rcj) {
448 phab = phab + 0.5 * (rha / rhb) * phb;
449 dvpdr = dvpdr + 0.5 * ((rha/rhb)*dphb +
450 phb*((drha/rhb) - (rha*drhb/rhb/rhb)));
451 }
452
453 break;
454
455 case eamDaw:
456 res = MixingMap[idat.atypes].phi->getValueAndDerivativeAt( *(idat.rij));
457 phab = res.first;
458 dvpdr = res.second;
459
460 break;
461 case eamUnknown:
462 default:
463
464 sprintf(painCave.errMsg,
465 "EAM::calcForce hit a mixing method it doesn't know about!\n"
466 );
467 painCave.severity = OPENMD_ERROR;
468 painCave.isFatal = 1;
469 simError();
470
471 }
472
473 drhoidr = drha;
474 drhojdr = drhb;
475
476 dudr = drhojdr* *(idat.dfrho1) + drhoidr* *(idat.dfrho2) + dvpdr;
477
478 *(idat.f1) += *(idat.d) * dudr / *(idat.rij);
479
480 // particlePot is the difference between the full potential and
481 // the full potential without the presence of a particular
482 // particle (atom1).
483 //
484 // This reduces the density at other particle locations, so we
485 // need to recompute the density at atom2 assuming atom1 didn't
486 // contribute. This then requires recomputing the density
487 // functional for atom2 as well.
488
489 *(idat.particlePot1) += data2.F->getValueAt( *(idat.rho2) - rha )
490 - *(idat.frho2);
491
492 *(idat.particlePot2) += data1.F->getValueAt( *(idat.rho1) - rhb)
493 - *(idat.frho1);
494
495 (*(idat.pot))[METALLIC_FAMILY] += phab;
496
497 *(idat.vpair) += phab;
498
499 return;
500
501 }
502
503 RealType EAM::getSuggestedCutoffRadius(pair<AtomType*, AtomType*> atypes) {
504 if (!initialized_) initialize();
505
506 RealType cut = 0.0;
507
508 map<AtomType*, EAMAtomData>::iterator it;
509
510 it = EAMMap.find(atypes.first);
511 if (it != EAMMap.end()) {
512 EAMAtomData data1 = (*it).second;
513 cut = data1.rcut;
514 }
515
516 it = EAMMap.find(atypes.second);
517 if (it != EAMMap.end()) {
518 EAMAtomData data2 = (*it).second;
519 if (data2.rcut > cut)
520 cut = data2.rcut;
521 }
522
523 return cut;
524 }
525 }
526

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