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root/OpenMD/branches/development/src/nonbonded/EAM.cpp
Revision: 1586
Committed: Tue Jun 21 06:34:35 2011 UTC (13 years, 10 months ago) by gezelter
File size: 15848 byte(s)
Log Message:
bug fixes

File Contents

# 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] Vardeman & Gezelter, in progress (2009).
40 */
41
42 #include <stdio.h>
43 #include <string.h>
44
45 #include <cmath>
46 #include "nonbonded/EAM.hpp"
47 #include "utils/simError.h"
48 #include "types/NonBondedInteractionType.hpp"
49
50
51 namespace OpenMD {
52
53 EAM::EAM() : name_("EAM"), initialized_(false), forceField_(NULL),
54 mixMeth_(eamJohnson), eamRcut_(0.0), haveCutoffRadius_(false) {}
55
56 EAMParam EAM::getEAMParam(AtomType* atomType) {
57
58 // Do sanity checking on the AtomType we were passed before
59 // building any data structures:
60 if (!atomType->isEAM()) {
61 sprintf( painCave.errMsg,
62 "EAM::getEAMParam was passed an atomType (%s) that does not\n"
63 "\tappear to be an embedded atom method (EAM) atom.\n",
64 atomType->getName().c_str());
65 painCave.severity = OPENMD_ERROR;
66 painCave.isFatal = 1;
67 simError();
68 }
69
70 GenericData* data = atomType->getPropertyByName("EAM");
71 if (data == NULL) {
72 sprintf( painCave.errMsg, "EAM::getEAMParam could not find EAM\n"
73 "\tparameters for atomType %s.\n",
74 atomType->getName().c_str());
75 painCave.severity = OPENMD_ERROR;
76 painCave.isFatal = 1;
77 simError();
78 }
79
80 EAMParamGenericData* eamData = dynamic_cast<EAMParamGenericData*>(data);
81 if (eamData == NULL) {
82 sprintf( painCave.errMsg,
83 "EAM::getEAMParam could not convert GenericData to EAMParam for\n"
84 "\tatom type %s\n", atomType->getName().c_str());
85 painCave.severity = OPENMD_ERROR;
86 painCave.isFatal = 1;
87 simError();
88 }
89
90 return eamData->getData();
91 }
92
93 CubicSpline* EAM::getZ(AtomType* atomType) {
94 EAMParam eamParam = getEAMParam(atomType);
95 int nr = eamParam.nr;
96 RealType dr = eamParam.dr;
97 vector<RealType> rvals;
98
99 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i) * dr);
100
101 CubicSpline* cs = new CubicSpline();
102 cs->addPoints(rvals, eamParam.Z);
103 return cs;
104 }
105
106 RealType EAM::getRcut(AtomType* atomType) {
107 EAMParam eamParam = getEAMParam(atomType);
108 return eamParam.rcut;
109 }
110
111 CubicSpline* EAM::getRho(AtomType* atomType) {
112 EAMParam eamParam = getEAMParam(atomType);
113 int nr = eamParam.nr;
114 RealType dr = eamParam.dr;
115 vector<RealType> rvals;
116
117 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i) * dr);
118
119 CubicSpline* cs = new CubicSpline();
120 cs->addPoints(rvals, eamParam.rho);
121 return cs;
122 }
123
124 CubicSpline* EAM::getF(AtomType* atomType) {
125 EAMParam eamParam = getEAMParam(atomType);
126 int nrho = eamParam.nrho;
127 RealType drho = eamParam.drho;
128 vector<RealType> rhovals;
129 vector<RealType> scaledF;
130
131 for (int i = 0; i < nrho; i++) {
132 rhovals.push_back(RealType(i) * drho);
133 scaledF.push_back( eamParam.F[i] * 23.06054 );
134 }
135
136 CubicSpline* cs = new CubicSpline();
137 cs->addPoints(rhovals, scaledF);
138 return cs;
139 }
140
141 CubicSpline* EAM::getPhi(AtomType* atomType1, AtomType* atomType2) {
142 EAMParam eamParam1 = getEAMParam(atomType1);
143 EAMParam eamParam2 = getEAMParam(atomType2);
144 CubicSpline* z1 = getZ(atomType1);
145 CubicSpline* z2 = getZ(atomType2);
146
147 // make the r grid:
148
149
150 // we need phi out to the largest value we'll encounter in the radial space;
151
152 RealType rmax = 0.0;
153 rmax = max(rmax, eamParam1.rcut);
154 rmax = max(rmax, eamParam1.nr * eamParam1.dr);
155
156 rmax = max(rmax, eamParam2.rcut);
157 rmax = max(rmax, eamParam2.nr * eamParam2.dr);
158
159 // use the smallest dr (finest grid) to build our grid:
160
161 RealType dr = min(eamParam1.dr, eamParam2.dr);
162
163 int nr = int(rmax/dr + 0.5);
164
165 vector<RealType> rvals;
166 for (int i = 0; i < nr; i++) rvals.push_back(RealType(i*dr));
167
168 // construct the pair potential:
169
170 vector<RealType> phivals;
171 RealType phi;
172 RealType r;
173 RealType zi, zj;
174
175 phivals.push_back(0.0);
176
177 for (int i = 1; i < rvals.size(); i++ ) {
178 r = rvals[i];
179
180 // only use z(r) if we're inside this atom's cutoff radius,
181 // otherwise, we'll use zero for the charge. This effectively
182 // means that our phi grid goes out beyond the cutoff of the
183 // pair potential
184
185 zi = r <= eamParam1.rcut ? z1->getValueAt(r) : 0.0;
186 zj = r <= eamParam2.rcut ? z2->getValueAt(r) : 0.0;
187
188 phi = 331.999296 * (zi * zj) / r;
189
190 phivals.push_back(phi);
191 }
192
193 CubicSpline* cs = new CubicSpline();
194 cs->addPoints(rvals, phivals);
195 return cs;
196 }
197
198 void EAM::setCutoffRadius( RealType rCut ) {
199 eamRcut_ = rCut;
200 haveCutoffRadius_ = true;
201 }
202
203 void EAM::initialize() {
204
205 // set up the mixing method:
206 ForceFieldOptions& fopts = forceField_->getForceFieldOptions();
207 string EAMMixMeth = fopts.getEAMMixingMethod();
208 toUpper(EAMMixMeth);
209
210 if (EAMMixMeth == "JOHNSON")
211 mixMeth_ = eamJohnson;
212 else if (EAMMixMeth == "DAW")
213 mixMeth_ = eamDaw;
214 else
215 mixMeth_ = eamUnknown;
216
217 // find all of the EAM atom Types:
218 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
219 ForceField::AtomTypeContainer::MapTypeIterator i;
220 AtomType* at;
221
222 for (at = atomTypes->beginType(i); at != NULL;
223 at = atomTypes->nextType(i)) {
224
225 if (at->isEAM())
226 addType(at);
227 }
228
229 // find all of the explicit EAM interactions (setfl):
230 ForceField::NonBondedInteractionTypeContainer* nbiTypes = forceField_->getNonBondedInteractionTypes();
231 ForceField::NonBondedInteractionTypeContainer::MapTypeIterator j;
232 NonBondedInteractionType* nbt;
233
234 for (nbt = nbiTypes->beginType(j); nbt != NULL;
235 nbt = nbiTypes->nextType(j)) {
236
237 if (nbt->isEAM()) {
238
239 pair<AtomType*, AtomType*> atypes = nbt->getAtomTypes();
240
241 GenericData* data = nbt->getPropertyByName("EAM");
242 if (data == NULL) {
243 sprintf( painCave.errMsg, "EAM::rebuildMixingMap could not find\n"
244 "\tEAM parameters for %s - %s interaction.\n",
245 atypes.first->getName().c_str(),
246 atypes.second->getName().c_str());
247 painCave.severity = OPENMD_ERROR;
248 painCave.isFatal = 1;
249 simError();
250 }
251
252 EAMMixingData* eamData = dynamic_cast<EAMMixingData*>(data);
253 if (eamData == NULL) {
254 sprintf( painCave.errMsg,
255 "EAM::rebuildMixingMap could not convert GenericData to\n"
256 "\tEAMMixingData for %s - %s interaction.\n",
257 atypes.first->getName().c_str(),
258 atypes.second->getName().c_str());
259 painCave.severity = OPENMD_ERROR;
260 painCave.isFatal = 1;
261 simError();
262 }
263
264 EAMMixingParam eamParam = eamData->getData();
265
266 vector<RealType> phiAB = eamParam.phi;
267 RealType dr = eamParam.dr;
268 int nr = eamParam.nr;
269
270 addExplicitInteraction(atypes.first, atypes.second, dr, nr, phiAB);
271 }
272 }
273 initialized_ = true;
274 }
275
276
277
278 void EAM::addType(AtomType* atomType){
279
280 EAMAtomData eamAtomData;
281
282 eamAtomData.rho = getRho(atomType);
283 eamAtomData.F = getF(atomType);
284 eamAtomData.Z = getZ(atomType);
285 eamAtomData.rcut = getRcut(atomType);
286
287 // add it to the map:
288 AtomTypeProperties atp = atomType->getATP();
289
290 pair<map<int,AtomType*>::iterator,bool> ret;
291 ret = EAMlist.insert( pair<int, AtomType*>(atp.ident, atomType) );
292 if (ret.second == false) {
293 sprintf( painCave.errMsg,
294 "EAM already had a previous entry with ident %d\n",
295 atp.ident);
296 painCave.severity = OPENMD_INFO;
297 painCave.isFatal = 0;
298 simError();
299 }
300
301 EAMMap[atomType] = eamAtomData;
302
303 // Now, iterate over all known types and add to the mixing map:
304
305 map<AtomType*, EAMAtomData>::iterator it;
306 for( it = EAMMap.begin(); it != EAMMap.end(); ++it) {
307
308 AtomType* atype2 = (*it).first;
309
310 EAMInteractionData mixer;
311 mixer.phi = getPhi(atomType, atype2);
312 mixer.explicitlySet = false;
313
314 pair<AtomType*, AtomType*> key1, key2;
315 key1 = make_pair(atomType, atype2);
316 key2 = make_pair(atype2, atomType);
317
318 MixingMap[key1] = mixer;
319 if (key2 != key1) {
320 MixingMap[key2] = mixer;
321 }
322 }
323 return;
324 }
325
326 void EAM::addExplicitInteraction(AtomType* atype1, AtomType* atype2,
327 RealType dr, int nr,
328 vector<RealType> phiVals) {
329
330 // in case these weren't already in the map
331 addType(atype1);
332 addType(atype2);
333
334 EAMInteractionData mixer;
335 CubicSpline* cs = new CubicSpline();
336 vector<RealType> rVals;
337
338 for (int i = 0; i < nr; i++) rVals.push_back(i * dr);
339
340 cs->addPoints(rVals, phiVals);
341 mixer.phi = cs;
342 mixer.explicitlySet = true;
343
344 pair<AtomType*, AtomType*> key1, key2;
345 key1 = make_pair(atype1, atype2);
346 key2 = make_pair(atype2, atype1);
347
348 MixingMap[key1] = mixer;
349 if (key2 != key1) {
350 MixingMap[key2] = mixer;
351 }
352 return;
353 }
354
355 void EAM::calcDensity(InteractionData &idat) {
356
357 if (!initialized_) initialize();
358
359 EAMAtomData data1 = EAMMap[idat.atypes.first];
360 EAMAtomData data2 = EAMMap[idat.atypes.second];
361
362 if (haveCutoffRadius_)
363 if ( *(idat.rij) > eamRcut_) return;
364
365 if ( *(idat.rij) < data1.rcut) {
366 *(idat.rho1) += data1.rho->getValueAt( *(idat.rij));
367
368
369 if ( *(idat.rij) < data2.rcut)
370 *(idat.rho2) += data2.rho->getValueAt( *(idat.rij));
371
372 return;
373 }
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
399
400 if (haveCutoffRadius_)
401 if ( *(idat.rij) > eamRcut_) return;
402
403 pair<RealType, RealType> res;
404
405
406 EAMAtomData data1 = EAMMap[idat.atypes.first];
407 EAMAtomData data2 = EAMMap[idat.atypes.second];
408
409 // get type-specific cutoff radii
410
411 RealType rci = data1.rcut;
412 RealType rcj = data2.rcut;
413
414 RealType rha(0.0), drha(0.0), rhb(0.0), drhb(0.0);
415 RealType pha(0.0), dpha(0.0), phb(0.0), dphb(0.0);
416 RealType phab(0.0), dvpdr(0.0);
417 RealType drhoidr, drhojdr, dudr;
418
419 if ( *(idat.rij) < rci) {
420 res = data1.rho->getValueAndDerivativeAt( *(idat.rij));
421 rha = res.first;
422 drha = res.second;
423
424 res = MixingMap[make_pair(idat.atypes.first, idat.atypes.first)].phi->getValueAndDerivativeAt( *(idat.rij) );
425 pha = res.first;
426 dpha = res.second;
427 }
428
429 if ( *(idat.rij) < rcj) {
430 res = data2.rho->getValueAndDerivativeAt( *(idat.rij) );
431 rhb = res.first;
432 drhb = res.second;
433
434 res = MixingMap[make_pair(idat.atypes.second, idat.atypes.second)].phi->getValueAndDerivativeAt( *(idat.rij) );
435 phb = res.first;
436 dphb = res.second;
437 }
438
439 switch(mixMeth_) {
440 case eamJohnson:
441
442 if ( *(idat.rij) < rci) {
443 phab = phab + 0.5 * (rhb / rha) * pha;
444 dvpdr = dvpdr + 0.5*((rhb/rha)*dpha +
445 pha*((drhb/rha) - (rhb*drha/rha/rha)));
446 }
447
448
449
450 if ( *(idat.rij) < rcj) {
451 phab = phab + 0.5 * (rha / rhb) * phb;
452 dvpdr = dvpdr + 0.5 * ((rha/rhb)*dphb +
453 phb*((drha/rhb) - (rha*drhb/rhb/rhb)));
454 }
455
456 break;
457
458 case eamDaw:
459 res = MixingMap[idat.atypes].phi->getValueAndDerivativeAt( *(idat.rij));
460 phab = res.first;
461 dvpdr = res.second;
462
463 break;
464 case eamUnknown:
465 default:
466
467 sprintf(painCave.errMsg,
468 "EAM::calcForce hit a mixing method it doesn't know about!\n"
469 );
470 painCave.severity = OPENMD_ERROR;
471 painCave.isFatal = 1;
472 simError();
473
474 }
475
476 drhoidr = drha;
477 drhojdr = drhb;
478
479 dudr = drhojdr* *(idat.dfrho1) + drhoidr* *(idat.dfrho2) + dvpdr;
480
481 *(idat.f1) += *(idat.d) * dudr / *(idat.rij);
482
483 // particlePot is the difference between the full potential and
484 // the full potential without the presence of a particular
485 // particle (atom1).
486 //
487 // This reduces the density at other particle locations, so we
488 // need to recompute the density at atom2 assuming atom1 didn't
489 // contribute. This then requires recomputing the density
490 // functional for atom2 as well.
491
492 *(idat.particlePot1) += data2.F->getValueAt( *(idat.rho2) - rha )
493 - *(idat.frho2);
494
495 *(idat.particlePot2) += data1.F->getValueAt( *(idat.rho1) - rhb)
496 - *(idat.frho1);
497
498 (*(idat.pot))[METALLIC_FAMILY] += phab;
499
500 *(idat.vpair) += phab;
501
502 return;
503
504 }
505
506 RealType EAM::getSuggestedCutoffRadius(pair<AtomType*, AtomType*> atypes) {
507 if (!initialized_) initialize();
508
509 RealType cut = 0.0;
510
511 map<AtomType*, EAMAtomData>::iterator it;
512
513 it = EAMMap.find(atypes.first);
514 if (it != EAMMap.end()) {
515 EAMAtomData data1 = (*it).second;
516 cut = data1.rcut;
517 }
518
519 it = EAMMap.find(atypes.second);
520 if (it != EAMMap.end()) {
521 EAMAtomData data2 = (*it).second;
522 if (data2.rcut > cut)
523 cut = data2.rcut;
524 }
525
526 return cut;
527 }
528 }
529

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