INTRAMOLECULAR STRAIN CONSTANTS: PYRAMIDAL $XY_{3}$ MOLECULES

Abstract

The potential function ${V}=\Sigma_{all bonds}\qquad {k}_{i}({d}_{i}-{D}_{i}^{0})^{2}+\Sigma_{all angles}\qquad {k}_{a}(a_{j}-{A}_{j}^{0})^{2}$, where $D^{0}_{i}$ and $A^{0}_{j}$ are the ""Strain free"" values of bond length and bond angle respectively, has been extended to $NH_{3}$-type molecules. Improved mathematics are described. Sufficient equations exist to determine all 6 parameters. Results in part support the conclusions made on $H_{2}O$-type molecules. There appears to be a ""preferred"" strain free bond angle.