In quantum chemistry, a natural bond orbital or NBO is a calculated bonding orbital with maximum electron density. The NBOs are one of a sequence of natural localized orbital sets that include "natural atomic orbitals" (NAO), "natural hybrid orbitals" (NHO), "natural bonding orbitals" (NBO) and "natural (semi-)localized molecular orbitals" (NLMO). These natural localized sets are intermediate between basis atomic orbitals (AO) and molecular orbitals (MO):
Atomic orbital → NAO → NHO → NBO → NLMO → Molecular orbital
Natural (localized) orbitals are used in computational chemistry to calculate the distribution of electron density in atoms and in bonds between atoms. They have the "maximum-occupancy character" in localized 1-center and 2-center regions of the molecule. Natural bond orbitals (NBOs) include the highest possible percentage of the electron density, ideally close to 2.000, providing the most accurate possible “natural Lewis structure” of ψ. A high percentage of electron density (denoted %-ρL), often found to be >99% for common organic molecules, correspond with an accurate natural Lewis structure.
The concept of natural orbitals was first introduced by Per-Olov Löwdin in 1955, to describe the unique set of orthonormal 1-electron functions that are intrinsic to the N-electron wavefunction.[1]
^Weinhold, Frank; Landis, Clark R. (2001). "Natural Bond Orbitals and Extensions of Localized Bonding Concepts" (PDF). Chemistry Education Research and Practice. 2 (2): 91–104. doi:10.1039/B1RP90011K.
and 20 Related for: Natural bond orbital information
localized orbital sets that include "natural atomic orbitals" (NAO), "natural hybrid orbitals" (NHO), "naturalbondingorbitals" (NBO) and "natural (semi-)localized...
s orbital combines with three valence-shell p orbitals to form four equivalent sp3 mixtures in a tetrahedral arrangement around the carbon to bond to...
discussions on localized molecular orbitals, see: naturalbondorbital and sigma-pi and equivalent-orbital models.) Molecular orbitals arise from allowed interactions...
change of formation ΔfH of −531 kJ/mol, is thermally very stable. Naturalbondorbital (NBO) analysis suggests weak aromaticity in borazine. In the NBO...
molecular orbitals only, and ni is the number of electrons occupying orbital i with coefficients cri and csi on atoms r and s respectively. Assuming a bond order...
Hydrographic Department Natural hybrid orbitals, one of a set of natural localized orbital sets in quantum chemistry, see Naturalbondorbital Takuu language,...
computational chemistry, natural resonance theory (NRT) is an iterative, variational functional embedded into the naturalbondorbital (NBO) program, commonly...
and 4pz orbitals and the lowest π orbital of the borole ring. Performing naturalbond analysis (NBO) on the model pointed to significant orbital interactions...
sophisticated theories are valence bond theory, which includes orbital hybridization and resonance, and molecular orbital theory which includes the linear...
Intrinsic bondorbitals (IBO) are localized molecular orbitals giving exact and non-empirical representations of wave functions. They are obtained by unitary...
OCLC 173809048. Weinhold, Frank; Landis, Clark R. (2005). Valency and Bonding: A NaturalBondOrbital Donor-Acceptor Perspective. Cambridge, UK: Cambridge University...
NBO may refer to: National Bank of Oman National Bank Open Naturalbondorbital, a model within quantum chemistry Network of Buddhist Organisations Network...
consists of a π orbital, resulting from donation from the planar P lone pair into the empty P orbital of the germylene center. Naturalbondorbital analysis...
the NaturalBondOrbital framework. In the staggered conformation, one C-H sigma bondingorbital donates electron density to the antibonding orbital of...
method used to evaluate chalcogen bonding specifically and a wide range of bonding generally is naturalbondorbital (NBO) analysis. NBO analysis distinguishes...
its pi electrons to the empty orbital of Pt, while its π* orbital accepts electrons from Pt. The semilocalized bonding cannot be adequately described...
Matheus P. (1 January 2013). "The anomeric effect on the basis of naturalbondorbital analysis". Organic & Biomolecular Chemistry. 11 (17): 2885–90. doi:10...
electron pair repulsion theory Molecular geometry Structural formula Naturalbondorbital IUPAC definition of Lewis formula Zumdahl, S. (2005) Chemical Principles...
partitioning theory, the quantum theory of atoms in molecules, naturalbondorbital theory, naturalorbitals for chemical valence and electron localization function...
FeIII: A Quantum Mechanical Study Based on DFT Computations and NaturalBondOrbital Analyses". Inorg. Chem. 40 (13): 3101–3112. doi:10.1021/ic001258t...