After reading this 2019 open-access paper, which states that NBO 3.0 correctly represents the valence participation of the np orbital(s) of transition metals, an explicit example of which participation being linked in the article(also open-access), but higher versions do not, I began to worry if the latest (2021) version of the NBO, NBO 7.0.10, still wrongly does not represent the valence participation of aforementioned orbitals in aforementioned atoms- a molecule that I've been designing in silico has a magnesium cluster inside it, and the paper explicitly says that NBO treats magnesium 3p orbitals as Rydberg orbitals, under which circumstances highly inaccurate results (cf. QTAIM, the most rigorous form of modern VB theory- again, see article) could occur.

Is this the case, i.e. NBO 7.0.10 treats magnesium 3p and (say) iron 4p as Rydberg orbitals, or is this (correctly) not the case?

  • $\begingroup$ I gave my +1 long ago, but do you have any update now that it has been more than 1 year since you asked this? $\endgroup$ Commented Dec 10, 2023 at 16:31


Browse other questions tagged .