Lattice Energy Estimation for Complex Inorganic Ionic Crystal

Abstract A novel connectivity index m G based on adjacency matrix of molecular graphs was proposed as follows: m G= Σ ( g i · g j · g k ···) 0.5 . The element g i of adjacency matrix was defined as g i = (1+ Z i 1.4 )/(1+ r i 1.4 ), where Z i and r i are the charge number and the thermochemical radius of ion i respectively, and the radii r i for metal ions are taken to be the Goldschmidt radius. The regression analysis by the connectivity index 1 G can provide a high‐quality QSPR model for the lattice energies of 245 complex inorganic ionic crystal samples. The results imply that the lattice energies may be expressed as a linear model of the connectivity index 1 G . For the linear model the correlation coefficient r and the standard error s are 0.9998 and 228.72 kJ/mol, respectively. The cross‐validation by the leave‐one‐out method demonstrates that the model is highly reliable from the point of view of statistics.