/// correlated sampling
WOSPotential::ValueType
WOSPotential::method2(ParticleSet& P)
{
double V0 = 0;
/// intialise the particles in WP;
WP->setP(P);
Domain domain; /// create domain;
double pe = 0.0;
double dpe = 0.0;
for(int irun = 0; irun < m_runs; irun++)
{
domain.runner = WP->R0; /// initialise runner
domain.in_device = true; /// runner is inside device
device->MaximumSphere(domain); /// calc d_{0}
domain.WalkOnSphere();
double vD0 = device->OC_contrib0(domain.radius,domain.runner,WP);
double vbare = device->OC_passage(V0,domain,WP);
WP->calcwt();
double vol = 0.0;
while(domain.in_device)
{
device->MaximumSphere(domain);
vol += device->contribk(domain,WP);
domain.WalkOnSphere();
vbare += device->OC_passage(V0,domain,WP);
}
vol *= WP->qwt; /// the half has been included
double vrun = vol + vbare + vD0;
pe += vrun;
dpe += vrun * vrun;
}
pe *= m_norm;
dpe *= m_norm;
dpe = ( dpe - pe * pe )/static_cast<double>(m_runs-1);
/// CHANGE FOR DMC, WARNING Tau is zero for VMC WOS
pe += dpe * Tau; // sigma^2 * Tau
// cout << "VWOS: "<< pe << '\t' << Tau << endl;
P.Properties(WOSVAR) = -dpe;
//P.Properties(WOSVAR) = dpe;
return pe;
}
/// correlated sampling
WOSPotential::ValueType
WOSPotential::method6(ParticleSet& P)
{
double V0 = 0;
/// intialise the particles in WP;
WP->setP(P);
Domain domain; /// create domain;
double pe = 0.0;
double dpe = 0.0;
for(int irun = 0; irun < m_runs; irun++)
{
domain.runner = WP->R0; /// initialise runner
domain.in_device = true; /// runner is inside device
device->MaximumSphere(domain); /// calc d_{0}
domain.WalkOnSphere();
double vD0 = device->OC_contrib0(domain.radius,domain.runner,WP);
double vbare = device->OC_passage(V0,domain,WP);
WP->calcwt();
double vol = 0.0;
while(domain.in_device)
{
device->MaximumSphere(domain);
vol += device->contribk(domain,WP);
domain.WalkOnSphere();
vbare += device->OC_passage(V0,domain,WP);
}
vol *= WP->qwt; /// the half has been included
double vrun = vol + vbare + vD0;
pe += vrun;
dpe += vrun * vrun;
}
pe *= m_norm;
dpe *= m_norm;
dpe = ( dpe - pe * pe )/static_cast<double>(m_runs-1);
double stsq = dpe * Tau * Tau;
double correction = 1.0 + stsq * (0.25 + stsq /
static_cast<double>(3*(m_runs+3))
) / static_cast<double>(2*(m_runs+1));
/// CHANGE FOR DMC, WARNING Tau is zero for VMC WOS
// pe += dpe * Tau; // sigma^2 * Tau
double pe1 = 0.0;
double dpe1 = 0.0;
for(int irun = 0; irun < 1; irun++)
{
domain.runner = WP->R0; /// initialise runner
domain.in_device = true; /// runner is inside device
device->MaximumSphere(domain); /// calc d_{0}
domain.WalkOnSphere();
double vD0 = device->OC_contrib0(domain.radius,domain.runner,WP);
double vbare = device->OC_passage(V0,domain,WP);
WP->calcwt();
double vol = 0.0;
while(domain.in_device)
{
device->MaximumSphere(domain);
vol += device->contribk(domain,WP);
domain.WalkOnSphere();
vbare += device->OC_passage(V0,domain,WP);
}
vol *= WP->qwt; /// the half has been included
double vrun = vol + vbare + vD0;
pe1 += vrun;
dpe1 += vrun * vrun;
}
//pe1 *= m_norm;
P.Properties(WOSVAR) = 2*(pe - pe1)/Tau + dpe;// * correction;
return pe1;
}
