  Recently, three successful antineutrino experiments (Daya Bay, Double Chooz,
and RENO) measured the neutrino mixing angle theta_13; however, significant
discrepancies were found, both in the absolute flux and spectral shape. In this
study, the antineutrino spectra were calculated by using the updated nuclear
database, and we found that the four isotopes antineutrino spectrum have all
contribution to the 5--7 MeV bump with ENDF/B-VII.1 fission yield. The bump can
be explained well using the updated library and more important isotopes
contribution to the bump were also given. In the last, the fission yield
correlation coefficient between the four isotopes were discussed, and found
that the correlation coefficients are very large.
