tools.py 文件源码

def find_fermi_SPB(cbm_vbm, c, T, tolerance=0.001, tolerance_loose=0.03, alpha=0.02, max_iter=1000):
    tp = get_tp(c)
    sgn = np.sign(c)
    m_eff = np.prod(cbm_vbm[tp]["eff_mass_xx"]) ** (1.0 / 3.0)
    c *= sgn
    initial_energy = cbm_vbm[tp]["energy"]
    fermi = initial_energy + 0.02
    iter = 0
    for iter in range(max_iter):
        calc_doping = 4 * pi * (2 * m_eff * m_e * k_B * T / hbar ** 2) ** 1.5 * fermi_integral(0.5, fermi, T,
                                                                                               initial_energy) * 1e-6 / e ** 1.5
        fermi += alpha * sgn * (calc_doping - c) / abs(c + calc_doping) * fermi
        relative_error = abs(calc_doping - c) / abs(c)
        if relative_error <= tolerance:
            # This here assumes that the SPB generator set the VBM to 0.0 and CBM=  gap + scissor
            if sgn < 0:
                return fermi
            else:
                return -(fermi - initial_energy)
    if relative_error > tolerance:
        raise ValueError("could NOT find a corresponding SPB fermi level after {} itenrations".format(max_iter))