# Predicting dissociation energy of diatomic iodine computationally

In one of my classes we used ORCA with three different functionals: BP86, B3LYP, and M06-L, all with the basis set def2-SVP. In addition to calculations we did it experimentally by a Deslandres table and a Birge-Sponer plot. The experimental values for the most part match the values given in NIST, however for the three functionals my $D_{0}^{"}$ value is twice as big as the value given in NIST, and I don't know why. Thanks!

• Welcome to chemistry.se! Feel free to take the tour to learn more about this site. In order to be actually able to help you, it would be good to if you could edit the values you have obtained/ researched into the question. Please also share what your thoughts are on the matter. – Martin - マーチン Apr 16 '16 at 13:38
• Are you making a distinction between $D_{0}$ and $D_{0}^{"}$? – pentavalentcarbon Sep 29 '16 at 1:59