qc.ao_spec: 
 Contains all information about the atomic orbitals
 The number of dictionaries corresponds to the number of contracted Gaussians
 Members of the dictionaries:
 “atom”
 Atom number (according to the input file, i.e., starting from 1) (
int )
 “coeffs”
 1st element exponent and 2nd element contraction coefficients of
the basis functions
numpy.ndarray (dtype= float ) with the shape (N_{primitives}, 2)
 “pnum”
 Number of number of primitives (
int )
 “exp_list” (optional)
 Exponents \((l_x,l_y,l_z)\) of the basis functions
 Only present if the order of the exponents deviate from the standard
molden order
list of tuple , i.e., [(l_x1,l_y1,l_z1), (l_x2,l_y2,l_z2), ...]
