gftool.bethe_gf_d2_z¶

gftool.bethe_gf_d2_z(z, half_bandwidth)¶

Second derivative of local Green’s function of Bethe lattice for infinite coordination number.

Parameters:	z : complex array_like or complex Green’s function is evaluated at complex frequency z half_bandwidth : float half-bandwidth of the DOS of the Bethe lattice The half_bandwidth corresponds to the nearest neighbor hopping t=D/2
Returns:	gf_d2_z : complex np.ndarray or complex Value of the Green’s function