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#include "Atom.hpp" |
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#include "SRI.hpp" |
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#include "AbstractClasses.hpp" |
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#include "SimInfo.hpp" |
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#include "ForceFields.hpp" |
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#include "Thermo.hpp" |
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#include "ReadWrite.hpp" |
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#include "Integrator.hpp" |
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#include "simError.h" |
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|
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|
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// Basic thermostating via Hoover, Phys.Rev.A, 1985, Vol. 31 (5) 1695-1697 |
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|
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NVT::NVT ( SimInfo *theInfo, ForceFields* the_ff): |
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Integrator( theInfo, the_ff ) |
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{ |
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chi = 0.0; |
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have_tau_thermostat = 0; |
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have_target_temp = 0; |
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} |
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|
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void NVT::moveA() { |
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|
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int i, j; |
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DirectionalAtom* dAtom; |
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double Tb[3], ji[3]; |
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double A[3][3], I[3][3]; |
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double angle, mass; |
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double vel[3], pos[3], frc[3]; |
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|
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double instTemp; |
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|
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instTemp = tStats->getTemperature(); |
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|
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// first evolve chi a half step |
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|
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chi += dt2 * ( instTemp / targetTemp - 1.0) / (tauThermostat*tauThermostat); |
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|
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for( i=0; i<nAtoms; i++ ){ |
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|
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atoms[i]->getVel( vel ); |
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atoms[i]->getPos( pos ); |
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atoms[i]->getFrc( frc ); |
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|
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mass = atoms[i]->getMass(); |
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|
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for (j=0; j < 3; j++) { |
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// velocity half step |
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vel[j] += dt2 * ((frc[j] / mass ) * eConvert - vel[j]*chi); |
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// position whole step |
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pos[j] += dt * vel[j]; |
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} |
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|
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atoms[i]->setVel( vel ); |
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atoms[i]->setPos( pos ); |
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|
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if( atoms[i]->isDirectional() ){ |
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|
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dAtom = (DirectionalAtom *)atoms[i]; |
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|
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// get and convert the torque to body frame |
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|
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dAtom->getTrq( Tb ); |
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dAtom->lab2Body( Tb ); |
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|
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// get the angular momentum, and propagate a half step |
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|
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dAtom->getJ( ji ); |
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|
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for (j=0; j < 3; j++) |
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ji[j] += dt2 * (Tb[j] * eConvert - ji[j]*chi); |
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|
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// use the angular velocities to propagate the rotation matrix a |
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// full time step |
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|
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dAtom->getA(A); |
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dAtom->getI(I); |
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|
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// rotate about the x-axis |
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angle = dt2 * ji[0] / I[0][0]; |
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this->rotate( 1, 2, angle, ji, A ); |
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|
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// rotate about the y-axis |
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angle = dt2 * ji[1] / I[1][1]; |
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this->rotate( 2, 0, angle, ji, A ); |
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|
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// rotate about the z-axis |
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angle = dt * ji[2] / I[2][2]; |
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this->rotate( 0, 1, angle, ji, A); |
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|
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// rotate about the y-axis |
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angle = dt2 * ji[1] / I[1][1]; |
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this->rotate( 2, 0, angle, ji, A ); |
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|
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// rotate about the x-axis |
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angle = dt2 * ji[0] / I[0][0]; |
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this->rotate( 1, 2, angle, ji, A ); |
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|
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dAtom->setJ( ji ); |
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dAtom->setA( A ); |
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} |
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} |
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} |
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|
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void NVT::moveB( void ){ |
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int i, j; |
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DirectionalAtom* dAtom; |
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double Tb[3], ji[3]; |
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double vel[3], frc[3]; |
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double mass; |
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|
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double instTemp; |
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|
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instTemp = tStats->getTemperature(); |
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chi += dt2 * ( instTemp / targetTemp - 1.0) / (tauThermostat*tauThermostat); |
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|
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for( i=0; i<nAtoms; i++ ){ |
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|
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atoms[i]->getVel( vel ); |
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atoms[i]->getFrc( frc ); |
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|
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mass = atoms[i]->getMass(); |
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|
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// velocity half step |
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for (j=0; j < 3; j++) |
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vel[j] += dt2 * ((frc[j] / mass ) * eConvert - vel[j]*chi); |
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|
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atoms[i]->setVel( vel ); |
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|
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if( atoms[i]->isDirectional() ){ |
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|
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dAtom = (DirectionalAtom *)atoms[i]; |
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|
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// get and convert the torque to body frame |
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|
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dAtom->getTrq( Tb ); |
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dAtom->lab2Body( Tb ); |
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|
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// get the angular momentum, and propagate a half step |
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|
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dAtom->getJ( ji ); |
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|
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for (j=0; j < 3; j++) |
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ji[j] += dt2 * (Tb[j] * eConvert - ji[j]*chi); |
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|
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|
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dAtom->setJ( ji ); |
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} |
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} |
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} |
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|
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int NVT::readyCheck() { |
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|
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// First check to see if we have a target temperature. |
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// Not having one is fatal. |
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|
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if (!have_target_temp) { |
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sprintf( painCave.errMsg, |
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"NVT error: You can't use the NVT integrator without a targetTemp!\n" |
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); |
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painCave.isFatal = 1; |
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simError(); |
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return -1; |
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} |
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|
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// We must set tauThermostat. |
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|
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if (!have_tau_thermostat) { |
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sprintf( painCave.errMsg, |
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"NVT error: If you use the constant temperature\n" |
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" integrator, you must set tauThermostat.\n"); |
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painCave.isFatal = 1; |
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simError(); |
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return -1; |
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} |
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return 1; |
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} |
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