Using the extended Hubbard model and sum-over-state method, we have calcula
ted the linear polarizability alpha and the third-order nonlinear polarizab
ility gamma for (C59N)(2). we find that (C59N)(2) has very big gamma value
(around 10(-32) esu), and its alpha and gamma values are bigger than those
of C59N. In particular, when 1.2 eV less than or equal to 3 omega, (C59N)(2
) has much larger gamma values than C59N.