Hi Rahul ,

BD is bonding orbital, LP is a lone pair. the starred versions are for the antibonding character.

this is well documented in the NBO paper;

Article Natural bond orbital methods

for the physical meaning of the LP* (the bonding/antibonding character of lone pair) have a look at the following paper;

Article Bonding/antibonding Character of "lone Pair" Molecular Orbit...

cheers

Rahul Suresh

"BD" 2-center bond

"CR" 1-center core pair

"BD*" 2-center antibond

"LP" 1-center valence lone pair

"RY*" 1-center Rydberg

“LP*” (Unfilled valence-shell nonbonding = empty 1 center

valence orbital).

Unstarred and starred labels corresponding to Lewis and non-Lewis NBOs, respectively.

Thank you so much and @Melek Hajji

Thank you. That was the answer I was looking for.

BD (1) is bonding natural orbital of sigma type;

BD* (1) is anti- bonding natural orbital of sigma* type;

BD (2) and BD* (2) are bonding and anti- bonding natural orbital of pi and pi* types, respectively;

LP is lone electron pair .

BD is a bonding orbital: the pair of atoms which are associated with this orbital are printed alongside.

LP is a lone pair: the associated atom is printed alongside.

BD* is an anti-bonding orbital: the pair of atoms which are associated with this orbital are printed alongside.

LP* is an anti-bonding character of lone pair.

In fact, a star-label is also conventionally used to identify out-of-phase ("anti-bonding") symmetry of a 2-center orbital about an inversion center or reflection plane, or an analogous more highly-noded phase pattern of a multi-center orbital.

Thank you

Hi everybody,

In my results of NBO analysis, I’m taking the highest value of E(2) which is supposed to give the strongest stabilization. But the highest E(2) value in my output is for both donor and acceptor orbitals showing antibonding type. is it reliable? And how can explain it?

Thanks a lot