def get_effective_potential(rr, n, N_electrons, xc_type):
## Get external potential
V_ext = -Z / rr[1:-1]
## Get single electron Hartree potential
V_sH = get_hartree_potential(rr[1:-1], n[1:-1])
## Get total Hartree potential
V_H = N_electrons * V_sH
## Get exchange correlation potential, type depends on function input
if xc_type == 0:
V_xc = 0
elif xc_type == 1:
V_xc = get_V_x(n[1:-1])
elif xc_type == 2:
V_xc = get_V_xc(n[1:-1])
elif xc_type == 3:
V_xc = get_V_xc_Vosko(n[1:-1])
else:
raise ValueError('Invalid exchange correlation type argument.')
## Add the potential terms to form the effective potential
V_eff = V_ext + V_H + V_xc
V_eff_diag = np.diagflat(V_eff)
return V_eff_diag
def test_helium_xc(rr, psi, tol, max_iter, verbose):
print(
"Calculating helium wave function and ground state energy with xc-Perdew..."
)
Z = 2
iteration_number = 0
E = 0
E_prev = E + 1
T0 = time.clock()
while abs(E - E_prev) > tol and iteration_number < max_iter:
iteration_number += 1
if verbose:
print("####### Iteration", iteration_number, "#######")
n = get_n(psi)
V_sH = get_hartree_potential(rr, n)
V_H = 2 * V_sH
V_xc = get_V_xc(n)
E_prev = E
E, psi = solve_ks(rr, Z, V_H, V_xc)
if verbose:
print("E =", E, "[Ha]")
print("ΔE =", E - E_prev, "[Ha]")
print("Time =", time.clock() - T0, "s")
print()
return psi, E