Theory of the Hyperfine Structure of NO Molecule. Electronic Structure

The calculation of the coupling constants of the magnetic and electric hfs of the NO molecule is done using the Heitler-London wave function with Hartree atomic wave function. The homopolar ground state is found to be expressed by a linear combination of four Slater determinants. This wave function is used with success to calculate the spin-orbit coupling constant and the Λ-type doublet separation as well as the hfs coupling constants. The "s-character" of the magnetic hfs is explained by the configuration interaction with an excited state of the N atom, in which one of the $2s$-electrons is promoted to the $3s$ orbital. The effective number of the odd electron in the electric hfs is 0.46, and Q for the N nucleus is 0.03×{}10^-24 cm². No ionic structure needs to be considered.