HarmonicExternalPotential.cpp

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//////////////////////////////////////////////////////////////////////////////////////
// This file is distributed under the University of Illinois/NCSA Open Source License.
// See LICENSE file in top directory for details.
//
// Copyright (c) 2016 Jeongnim Kim and QMCPACK developers.
//
// File developed by: Jaron T. Krogel, krogeljt@ornl.gov, Oak Ridge National Laboratory
//                    Mark A. Berrill, berrillma@ornl.gov, Oak Ridge National Laboratory
//
// File created by: Jaron T. Krogel, krogeljt@ornl.gov, Oak Ridge National Laboratory
//////////////////////////////////////////////////////////////////////////////////////


#include "HarmonicExternalPotential.h"
#include "OhmmsData/AttributeSet.h"


namespace qmcplusplus
{
bool HarmonicExternalPotential::put(xmlNodePtr cur)
{
  using std::sqrt;

  mass   = -1.0;
  energy = -1.0;
  length = -1.0;
  center = 0.0;

  OhmmsAttributeSet attrib;
  attrib.add(mass, "mass");
  attrib.add(energy, "frequency");
  attrib.add(energy, "energy");
  attrib.add(length, "length");
  attrib.add(center, "center");
  attrib.put(cur);

  if (energy < 0.0)
    energy = 1.0;
  if (mass < 0.0 && length < 0.0)
    length = 1.0;
  if (mass < 0.0)
    mass = 1.0 / (energy * length * length);
  else if (length < 0.0)
    length = 1.0 / sqrt(mass * energy);

  return true;
}


bool HarmonicExternalPotential::get(std::ostream& os) const
{
  os << "External harmonic potential" << std::endl;
  return true;
}


std::unique_ptr<OperatorBase> HarmonicExternalPotential::makeClone(ParticleSet& P, TrialWaveFunction& psi)
{
  return std::make_unique<HarmonicExternalPotential>(*this);
}


HarmonicExternalPotential::Return_t HarmonicExternalPotential::evaluate(ParticleSet& P)
{
#if !defined(REMOVE_TRACEMANAGER)
  if (streaming_particles_)
    value_ = evaluate_sp(P);
  else
  {
#endif
    value_             = 0.0;
    RealType prefactor = .5 * energy / (length * length);
    for (int i = 0; i < P.getTotalNum(); ++i)
    {
      PosType r = P.R[i] - center;
      value_ += prefactor * dot(r, r);
    }
#if !defined(REMOVE_TRACEMANAGER)
  }
#endif
  return value_;
}


#if !defined(REMOVE_TRACEMANAGER)
HarmonicExternalPotential::Return_t HarmonicExternalPotential::evaluate_sp(ParticleSet& P)
{
  Array<TraceReal, 1>& V_samp = *V_sample;
  value_                      = 0.0;
  RealType prefactor          = .5 * energy / (length * length);
  for (int i = 0; i < P.getTotalNum(); ++i)
  {
    PosType r   = P.R[i] - center;
    RealType v1 = prefactor * dot(r, r);
    V_samp(i)   = v1;
    value_ += v1;
  }
  return value_;
}
#endif

} // namespace qmcplusplus