LangevinHullForceModifier.hpp

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 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your
 * research, please cite the appropriate papers when you publish your
 * work.  Good starting points are:
 *
 * [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).
 * [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).
 * [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008).
 * [4] Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
 * [5] Kuang & Gezelter, Mol. Phys., 110, 691-701 (2012).
 * [6] Lamichhane, Gezelter & Newman, J. Chem. Phys. 141, 134109 (2014).
 * [7] Lamichhane, Newman & Gezelter, J. Chem. Phys. 141, 134110 (2014).
 * [8] Bhattarai, Newman & Gezelter, Phys. Rev. B 99, 094106 (2019).
 */
 
#ifndef INTEGRATOR_LANGEVINHULLFORCEMODIFIER_HPP
#define INTEGRATOR_LANGEVINHULLFORCEMODIFIER_HPP
 
#include <map>
#include <memory>
#include <vector>
 
#include "brains/ForceManager.hpp"
#include "brains/Thermo.hpp"
#include "brains/Velocitizer.hpp"
#include "math/Hull.hpp"
#include "math/Triangle.hpp"
#include "primitives/Molecule.hpp"
#include "utils/RandNumGen.hpp"
 
using namespace std;
namespace OpenMD {
 
  /**
   * @class LangevinHullForceModifier
   * Force modifier for NPT Langevin Hull Dynamics applying friction
   * and random forces as well as torques.  Stochastic force is
   * determined by the area of surface triangles on the convex hull.
   * See: Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011),
   *      and Kohanoff et al. CHEMPHYSCHEM 6, 1848-1852 (2005).
   */
  class LangevinHullForceModifier : public ForceModifier {
  public:
    LangevinHullForceModifier(SimInfo* info);
    ~LangevinHullForceModifier();
 
    void modifyForces() override;
 
  private:
    std::vector<Vector3d> genTriangleForces(int nTriangles);
 
    Globals* simParams_;
    Utils::RandNumGenPtr randNumGen_;
    std::normal_distribution<RealType> forceDistribution_;
    std::unique_ptr<Velocitizer> veloMunge {nullptr};
 
    RealType dt_;
    RealType targetTemp_;
    RealType targetPressure_;
    RealType viscosity_;
 
    enum HullTypeEnum { hullConvex, hullAlphaShape, hullUnknown };
 
    std::map<string, HullTypeEnum> stringToEnumMap_;
    HullTypeEnum hullType_;
 
    bool doThermalCoupling_;
    bool doPressureCoupling_;
 
    Hull* surfaceMesh_;
    std::vector<StuntDouble*> localSites_;
  };
}  // namespace OpenMD
 
#endif  // INTEGRATOR_LANGEVINHULLFORCEMODIFIER_HPP