jscaux/ABACUS-v1
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Clean up sources up to (before) src/SCAN.

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J.-S. Caux
2018-02-11 10:01:56 +01:00
parent d337885305
commit e7dd24d337
28 changed files with 1046 additions and 2987 deletions
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src/ODSLF/ODSLF_Chem_Pot.cc
-119
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@@ -16,125 +16,6 @@ Purpose: calculates the chemical potential.
namespace ABACUS {
/*
DP Ezero (DP Delta, int N, int M)
{
// Returns the energy of the ground state with M down spins
if (M < 0 || M > N/2) ABACUSerror("M out of bounds in Ezero.");
DP E = -1.0; // sentinel value
if (M == 0) E = N * Delta/4.0;
else {
Heis_Chain BD1(1.0, Delta, 0.0, N);
Vect_INT Nrapidities_groundstate(0, BD1.Nstrings);
Nrapidities_groundstate[0] = M;
ODSLF_Base baseconfig_groundstate(BD1, Nrapidities_groundstate);
if ((Delta > 0.0) && (Delta < 1.0)) {
ODSLF_XXZ_Bethe_State groundstate(BD1, baseconfig_groundstate);
groundstate.Compute_All(true);
E = groundstate.E;
}
else if (Delta == 1.0) {
XXX_Bethe_State groundstate(BD1, baseconfig_groundstate);
groundstate.Compute_All(true);
E = groundstate.E;
}
else if (Delta > 1.0) {
XXZ_gpd_Bethe_State groundstate(BD1, baseconfig_groundstate);
groundstate.Compute_All(true);
E = groundstate.E;
}
else ABACUSerror("Anisotropy out of bounds in Ezero.");
}
return(E);
}
DP H_vs_M (DP Delta, int N, int M)
{
// Assumes dE/dM = 0 = dE_0/dM + h, with dE_0/dM = E_0(M) - E_0 (M - 1)
DP H = 0.0;
if (2*M == N) H = 0.0;
else if (Delta <= 1.0) H = Ezero (Delta, N, M - 1) - Ezero (Delta, N, M);
return(H);
}
DP HZmin (DP Delta, int N, int M, Vect_DP& Ezero_ref)
{
if (M < 0 || M > N/2 - 1) {
cout << "M = " << M << endl;
ABACUSerror("M out of bounds in HZmin.");
}
if (Ezero_ref[M] == -1.0) Ezero_ref[M] = Ezero(Delta, N, M);
if (Ezero_ref[M + 1] == -1.0) Ezero_ref[M + 1] = Ezero(Delta, N, M + 1);
return(Ezero_ref[M] - Ezero_ref[M + 1]);
}
int M_vs_H (DP Delta, int N, DP HZ)
{
// Returns the value of M for given field HZ
if (HZ < 0.0) ABACUSerror("Please use a positive field in M_vs_H.");
else if (HZ == 0.0) return(N/2);
// Here, -1.0 is a sentinel value.
Vect_DP Ezero(-1.0, N/2 + 1); // contains the GSE[M].
// We look for M s.t. HZmin[M] < HZ <= HZmin[M + 1]
int M_actual = N/4; // start somewhere in middle
int M_step = N/8 - 1; // step
DP HZmin_actual = 0.0;
DP HZmax_actual = 0.0;
bool M_found = false;
if (HZ >= 1.0 + Delta) M_actual = 0; // saturation
else {
HZmin_actual = HZmin (Delta, N, M_actual, Ezero);
HZmax_actual = HZmin (Delta, N, M_actual - 1, Ezero);
while (!M_found) {
if (HZmin_actual > HZ) M_actual += M_step;
else if (HZmax_actual <= HZ) M_actual -= M_step;
M_step = (M_step + 1)/2;
HZmin_actual = HZmin (Delta, N, M_actual, Ezero);
HZmax_actual = HZmin (Delta, N, M_actual - 1, Ezero);
M_found = (HZmin_actual < HZ && HZ <= HZmax_actual);
//cout << "M_actual = " << M_actual << "\tM_step = " << M_step
// << "\tHZmin_actual = " << HZmin_actual << "\tHZmax_actual = " << HZmax_actual << "\tHZ = " << HZ << "\t" << M_found << endl;
}
}
//cout << "M found = " << M_actual << "\tHZmax = " << Ezero[M_actual] - Ezero[M_actual + 1] << "\tHZmin = " << Ezero[M_actual - 1] - Ezero[M_actual] << endl;
return(M_actual);
}
*/
DP Chemical_Potential (const ODSLF_Bethe_State& RefState)
{
return(-H_vs_M (RefState.chain.Delta, RefState.chain.Nsites, RefState.base.Mdown)); // - sign since E_{M+1} - E_M = -H