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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, 24107 (2008). |
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* [4] Vardeman & Gezelter, in progress (2009). |
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*/ |
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|
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#include <stdio.h> |
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#include <string.h> |
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|
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#include <cmath> |
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#include "nonbonded/GB.hpp" |
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#include "utils/simError.h" |
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|
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using namespace std; |
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namespace OpenMD { |
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|
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GB::GB() : name_("GB"), initialized_(false), mu_(2.0), nu_(1.0), forceField_(NULL) {} |
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|
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GayBerneParam GB::getGayBerneParam(AtomType* atomType) { |
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|
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// Do sanity checking on the AtomType we were passed before |
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// building any data structures: |
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if (!atomType->isGayBerne()) { |
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sprintf( painCave.errMsg, |
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"GB::getGayBerneParam was passed an atomType (%s) that does\n" |
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"\tnot appear to be a Gay-Berne atom.\n", |
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atomType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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DirectionalAtomType* daType = dynamic_cast<DirectionalAtomType*>(atomType); |
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GenericData* data = daType->getPropertyByName("GayBerne"); |
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if (data == NULL) { |
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sprintf( painCave.errMsg, "GB::getGayBerneParam could not find\n" |
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"\tGay-Berne parameters for atomType %s.\n", |
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daType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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GayBerneParamGenericData* gbData = dynamic_cast<GayBerneParamGenericData*>(data); |
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if (gbData == NULL) { |
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sprintf( painCave.errMsg, |
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"GB::getGayBerneParam could not convert GenericData to\n" |
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"\tGayBerneParamGenericData for atom type %s\n", |
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daType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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return gbData->getData(); |
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} |
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|
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LJParam GB::getLJParam(AtomType* atomType) { |
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|
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// Do sanity checking on the AtomType we were passed before |
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// building any data structures: |
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if (!atomType->isLennardJones()) { |
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sprintf( painCave.errMsg, |
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"GB::getLJParam was passed an atomType (%s) that does not\n" |
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"\tappear to be a Lennard-Jones atom.\n", |
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atomType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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GenericData* data = atomType->getPropertyByName("LennardJones"); |
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if (data == NULL) { |
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sprintf( painCave.errMsg, "GB::getLJParam could not find Lennard-Jones\n" |
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"\tparameters for atomType %s.\n", atomType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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LJParamGenericData* ljData = dynamic_cast<LJParamGenericData*>(data); |
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if (ljData == NULL) { |
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sprintf( painCave.errMsg, |
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"GB::getLJParam could not convert GenericData to LJParam for\n" |
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"\tatom type %s\n", atomType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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return ljData->getData(); |
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} |
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|
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RealType GB::getLJEpsilon(AtomType* atomType) { |
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LJParam ljParam = getLJParam(atomType); |
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return ljParam.epsilon; |
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} |
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RealType GB::getLJSigma(AtomType* atomType) { |
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LJParam ljParam = getLJParam(atomType); |
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return ljParam.sigma; |
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} |
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|
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void GB::initialize() { |
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|
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ForceFieldOptions& fopts = forceField_->getForceFieldOptions(); |
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mu_ = fopts.getGayBerneMu(); |
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nu_ = fopts.getGayBerneNu(); |
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ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes(); |
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ForceField::AtomTypeContainer::MapTypeIterator i; |
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AtomType* at; |
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|
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// GB handles all of the GB-GB interactions as well as GB-LJ cross |
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// interactions: |
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|
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for (at = atomTypes->beginType(i); at != NULL; |
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at = atomTypes->nextType(i)) { |
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|
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if (at->isGayBerne() || at->isLennardJones()) |
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addType(at); |
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} |
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|
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initialized_ = true; |
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} |
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|
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void GB::addType(AtomType* atomType){ |
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// add it to the map: |
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AtomTypeProperties atp = atomType->getATP(); |
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|
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pair<map<int,AtomType*>::iterator,bool> ret; |
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ret = GBMap.insert( pair<int, AtomType*>(atp.ident, atomType) ); |
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if (ret.second == false) { |
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sprintf( painCave.errMsg, |
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"GB already had a previous entry with ident %d\n", |
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atp.ident); |
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painCave.severity = OPENMD_INFO; |
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painCave.isFatal = 0; |
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simError(); |
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} |
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|
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RealType d1, l1, e1, er1, dw1; |
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|
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if (atomType->isGayBerne()) { |
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GayBerneParam gb1 = getGayBerneParam(atomType); |
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d1 = gb1.GB_d; |
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l1 = gb1.GB_l; |
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e1 = gb1.GB_eps; |
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er1 = gb1.GB_eps_ratio; |
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dw1 = gb1.GB_dw; |
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} else if (atomType->isLennardJones()) { |
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d1 = getLJSigma(atomType) / sqrt(2.0); |
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e1 = getLJEpsilon(atomType); |
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l1 = d1; |
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er1 = 1.0; |
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dw1 = 1.0; |
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} else { |
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sprintf( painCave.errMsg, |
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"GB::addType was passed an atomType (%s) that does not\n" |
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"\tappear to be a Gay-Berne or Lennard-Jones atom.\n", |
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atomType->getName().c_str()); |
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painCave.severity = OPENMD_ERROR; |
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painCave.isFatal = 1; |
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simError(); |
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} |
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|
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|
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// Now, iterate over all known types and add to the mixing map: |
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|
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map<int, AtomType*>::iterator it; |
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for( it = GBMap.begin(); it != GBMap.end(); ++it) { |
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|
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AtomType* atype2 = (*it).second; |
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|
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RealType d2, l2, e2, er2, dw2; |
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|
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if (atype2->isGayBerne()) { |
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GayBerneParam gb2 = getGayBerneParam(atype2); |
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d2 = gb2.GB_d; |
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l2 = gb2.GB_l; |
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e2 = gb2.GB_eps; |
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er2 = gb2.GB_eps_ratio; |
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dw2 = gb2.GB_dw; |
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} else if (atype2->isLennardJones()) { |
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d2 = getLJSigma(atype2) / sqrt(2.0); |
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e2 = getLJEpsilon(atype2); |
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l2 = d2; |
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er2 = 1.0; |
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dw2 = 1.0; |
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} |
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|
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GBInteractionData mixer; |
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|
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// Cleaver paper uses sqrt of squares to get sigma0 for |
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// mixed interactions. |
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|
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mixer.sigma0 = sqrt(d1*d1 + d2*d2); |
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mixer.xa2 = (l1*l1 - d1*d1)/(l1*l1 + d2*d2); |
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mixer.xai2 = (l2*l2 - d2*d2)/(l2*l2 + d1*d1); |
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mixer.x2 = (l1*l1 - d1*d1) * (l2*l2 - d2*d2) / |
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((l2*l2 + d1*d1) * (l1*l1 + d2*d2)); |
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|
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// assumed LB mixing rules for now: |
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|
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mixer.dw = 0.5 * (dw1 + dw2); |
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mixer.eps0 = sqrt(e1 * e2); |
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|
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RealType er = sqrt(er1 * er2); |
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RealType ermu = pow(er,(1.0 / mu_)); |
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RealType xp = (1.0 - ermu) / (1.0 + ermu); |
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RealType ap2 = 1.0 / (1.0 + ermu); |
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|
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mixer.xp2 = xp * xp; |
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mixer.xpap2 = xp * ap2; |
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mixer.xpapi2 = xp / ap2; |
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|
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// only add this pairing if at least one of the atoms is a Gay-Berne atom |
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|
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if (atomType->isGayBerne() || atype2->isGayBerne()) { |
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|
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pair<AtomType*, AtomType*> key1, key2; |
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key1 = make_pair(atomType, atype2); |
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key2 = make_pair(atype2, atomType); |
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|
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MixingMap[key1] = mixer; |
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if (key2 != key1) { |
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MixingMap[key2] = mixer; |
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} |
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} |
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} |
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} |
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|
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void GB::calcForce(InteractionData idat) { |
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|
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if (!initialized_) initialize(); |
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|
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pair<AtomType*, AtomType*> key = make_pair(idat.atype1, idat.atype2); |
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GBInteractionData mixer = MixingMap[key]; |
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|
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RealType sigma0 = mixer.sigma0; |
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RealType dw = mixer.dw; |
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RealType eps0 = mixer.eps0; |
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RealType x2 = mixer.x2; |
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RealType xa2 = mixer.xa2; |
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RealType xai2 = mixer.xai2; |
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RealType xp2 = mixer.xp2; |
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RealType xpap2 = mixer.xpap2; |
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RealType xpapi2 = mixer.xpapi2; |
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|
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Vector3d ul1 = idat.A1.getRow(2); |
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Vector3d ul2 = idat.A2.getRow(2); |
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|
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RealType a, b, g; |
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|
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bool i_is_LJ = idat.atype1->isLennardJones(); |
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bool j_is_LJ = idat.atype2->isLennardJones(); |
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|
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if (i_is_LJ) { |
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a = 0.0; |
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ul1 = V3Zero; |
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} else { |
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a = dot(idat.d, ul1); |
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} |
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|
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if (j_is_LJ) { |
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b = 0.0; |
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ul2 = V3Zero; |
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} else { |
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b = dot(idat.d, ul2); |
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} |
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|
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if (i_is_LJ || j_is_LJ) |
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g = 0.0; |
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else |
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g = dot(ul1, ul2); |
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|
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RealType au = a / idat.rij; |
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RealType bu = b / idat.rij; |
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|
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RealType au2 = au * au; |
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RealType bu2 = bu * bu; |
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RealType g2 = g * g; |
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|
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RealType H = (xa2 * au2 + xai2 * bu2 - 2.0*x2*au*bu*g) / (1.0 - x2*g2); |
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RealType Hp = (xpap2*au2 + xpapi2*bu2 - 2.0*xp2*au*bu*g) / (1.0 - xp2*g2); |
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|
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RealType sigma = sigma0 / sqrt(1.0 - H); |
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RealType e1 = 1.0 / sqrt(1.0 - x2*g2); |
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RealType e2 = 1.0 - Hp; |
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RealType eps = eps0 * pow(e1,nu_) * pow(e2,mu_); |
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RealType BigR = dw*sigma0 / (idat.rij - sigma + dw*sigma0); |
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|
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RealType R3 = BigR*BigR*BigR; |
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RealType R6 = R3*R3; |
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RealType R7 = R6 * BigR; |
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RealType R12 = R6*R6; |
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RealType R13 = R6*R7; |
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|
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RealType U = idat.vdwMult * 4.0 * eps * (R12 - R6); |
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|
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RealType s3 = sigma*sigma*sigma; |
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RealType s03 = sigma0*sigma0*sigma0; |
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|
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RealType pref1 = - idat.vdwMult * 8.0 * eps * mu_ * (R12 - R6) / (e2 * idat.rij); |
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|
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RealType pref2 = idat.vdwMult * 8.0 * eps * s3 * (6.0*R13 - 3.0*R7) /(dw*idat.rij*s03); |
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|
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RealType dUdr = - (pref1 * Hp + pref2 * (sigma0*sigma0*idat.rij/s3 + H)); |
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|
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RealType dUda = pref1 * (xpap2*au - xp2*bu*g) / (1.0 - xp2 * g2) |
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+ pref2 * (xa2 * au - x2 *bu*g) / (1.0 - x2 * g2); |
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|
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RealType dUdb = pref1 * (xpapi2*bu - xp2*au*g) / (1.0 - xp2 * g2) |
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+ pref2 * (xai2 * bu - x2 *au*g) / (1.0 - x2 * g2); |
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|
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RealType dUdg = 4.0 * eps * nu_ * (R12 - R6) * x2 * g / (1.0 - x2*g2) |
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+ 8.0 * eps * mu_ * (R12 - R6) * (xp2*au*bu - Hp*xp2*g) / |
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(1.0 - xp2 * g2) / e2 + 8.0 * eps * s3 * (3.0 * R7 - 6.0 * R13) * |
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(x2 * au * bu - H * x2 * g) / (1.0 - x2 * g2) / (dw * s03); |
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|
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|
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Vector3d rhat = idat.d / idat.rij; |
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Vector3d rxu1 = cross(idat.d, ul1); |
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Vector3d rxu2 = cross(idat.d, ul2); |
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Vector3d uxu = cross(ul1, ul2); |
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|
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idat.pot += U*idat.sw; |
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idat.f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2; |
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idat.t1 += dUda * rxu1 - dUdg * uxu; |
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idat.t2 += dUdb * rxu2 - dUdg * uxu; |
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idat.vpair += U*idat.sw; |
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|
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return; |
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|
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} |
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|
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RealType GB::getSuggestedCutoffRadius(AtomType* at1, AtomType* at2) { |
| 371 |
if (!initialized_) initialize(); |
| 372 |
|
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RealType cut = 0.0; |
| 374 |
|
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if (at1->isGayBerne()) { |
| 376 |
GayBerneParam gb1 = getGayBerneParam(at1); |
| 377 |
RealType d1 = gb1.GB_d; |
| 378 |
RealType l1 = gb1.GB_l; |
| 379 |
// sigma is actually sqrt(2)*l for prolate ellipsoids |
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cut = max(cut, 2.5 * sqrt(2.0) * max(d1, l1)); |
| 381 |
} else if (at1->isLennardJones()) { |
| 382 |
cut = max(cut, 2.5 * getLJSigma(at1)); |
| 383 |
} |
| 384 |
|
| 385 |
if (at2->isGayBerne()) { |
| 386 |
GayBerneParam gb2 = getGayBerneParam(at2); |
| 387 |
RealType d2 = gb2.GB_d; |
| 388 |
RealType l2 = gb2.GB_l; |
| 389 |
cut = max(cut, 2.5 * sqrt(2.0) * max(d2, l2)); |
| 390 |
} else if (at1->isLennardJones()) { |
| 391 |
cut = max(cut, 2.5 * getLJSigma(at2)); |
| 392 |
} |
| 393 |
|
| 394 |
return cut; |
| 395 |
} |
| 396 |
} |
| 397 |
|
