B(M-L) are derived for a wide range of aquo ions and for a few complexes. The non bonding electrons of central metal atom or ion remain unaffected and do not take part in chemical bonding. You probably should spend a fair amount of time discussing the σ and π interactions between manganese and the cyanido ligands including pointing out the high covalency of the $\ce$. values of the coordinate bond energy terms for metal-ligand bonds. It is important to understand the bonding situation in complexes which can be difficult and, yes, complex.