is the total kinetic energy of the fragments. The steepest-descent approximation does indeed reduce to this closed-form expression, with all fragments in their ground states, as T$_{0}$ → 0 , except for a multiplicative factor R (3 ( n − 1) / 2) that substitutes a Stirling approximation for the gamma function in the denominator, This factor is approximately 1.06 for n = 2 , 1.03 for n = 3 and decreases to one as n increases. To get an idea of the differences to be expected between a calculation using the usual FBM and its generalized version, we compare calculations using the two models here. To set a context, we consider the case of a 62 MeV proton incident on $^{16}$O, for which double differential emission data exist [28]. We describe the initial stage of the reaction using the Monte Carlo exciton cascade model of Blann and Chadwick [29, 30], which provides a good description of the double differential data. This model simulates the pre-equilibrium stage of a nucleon-nucleus collison by following a cascade of particle-particle and particle- hole interactions together with particle emission, until all remaining nucleons have energy smaller than their separation energy from the residual nucleus. When it is applied to the case of a 62 MeV proton incident on $^{16}$O, it furnishes a $^{16}$O primary compound nucleus population corresponding to 66% of the reaction cross section of approximately 400 mb, with the primary populations of the $^{15}$O and $^{15}$N compound nuclei accounting for another 32% of the reaction cross section. The distribution in excitation energy of the compound populations is extremely broad, with that of $^{16}$O extending from zero to the center-of-mass energy of 58.4 MeV with a peak at about 50 MeV. Using this as motivation, we compare the results for the Fermi breakup of $^{16}$O at an excitation energy of 50 MeV including 1) only the ground states of the fragments, 2) the ground states and particle-bound states of the fragments and 3) the ground states and all excited states of the fragments found in the RIPL-2 nuclear level library [31]. We note that the calculation including ground states and particle-bound states is not entirely consistent as it includes particle-unbound ground states, such as those of $^{5}$He and $^{8}$Be, which make 7 III. COMPARISON OF THE FBM AND THE GENERALIZED FBM R ( h ) = Γ ( h ) / exp [( h − 1 / 2) ln ( h ) − h + ln (2 π ) / 2] .