2ND MOMENT SCALING, MOLECULES AND BOND BREAKING

We apply the second moment scaling hypothesis to correctly predict the structures of the molecular main group elements. We show that second moment scaling in conjunction with simple Huckel theory correctly accounts for the structures of diamond, N2, O2, F2, black phosphorus, S8, Cl2, Te and I2. We extend this method to several more complex systems such as the ZrSi2, SmSb2 and Cu2Sb structure types as well as alpha-P4S, and S4(2-). We also consider the site preference problem in alpha-P4S4 and S2Cl2. Finally, we account for our results using a moments analysis.