Knowledge Bank

Using ab-initio methods we have studied as a function of angle the spin dipole-spin dipole contribution to the zero field splitting parameters D and E for the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}B1$ state of $CH2$ and $CF2$ and the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$A^{\prime\prime} state of HCF. We find the decrease in D upon going from $CH2$ to CHF to be $0.026cm-1$ while going from CHF to $CF2$ we obtain $0.023cm-1$. In addition we find a good correlation between E and the number of s electrons in the in-plane ($\sigma$) density and a reasonable correlation between E/D and the percent s character in this same density.