An Ab Initio Study of the Zero Field Splitting Parameters of B13 Methylene

Abstract

The spin–dipole contribution to the zero field splitting parameters of methylene in the ${}^3{B}_1$ state has been studied as a function of geometry. At the computed equilibrium geometry of $R_{\mathrm{CH}}\text{\hspace{0.17em}=\hspace{0.17em}1.05 Å}$ and $\text{θ\hspace{0.17em}=\hspace{0.17em}132.5°}$ we find $\text{D\hspace{0.17em}=\hspace{0.17em}0.71}{\mathrm{cm}}^{\text{−1}}$ while $\text{E\hspace{0.17em}=\hspace{0.17em}0.05}{\mathrm{cm}}^{\text{−1}}$ (experimental= 0.69 and 0.003 cm⁻¹, respectively). The dependence of $\mathrm{E\hspace{0.17em}/\hspace{0.17em}D}$ on bond angle, bond length, and percent $s$ character in the lone‐pair density is examined. Our results suggest that the spin–orbit contribution to $D$ and $E$ in methylene is negligible.