"It is nice to know that the computer understands the problem, but I would
like to understand it too."
- Eugene Wigner|
Through their close association with elementary Lewis structure
diagrams, NBOs provide a direct link to familiar valency
and bonding concepts. Unlike delocalized MOs
(whose sprawling forms vary bewilderingly even between closely
related systems), NBOs are highly conserved
and transferable from one molecular environment
NBOs are intrinsic realizations
of orbital-type bonding concepts
as originally envisioned by Pauling, Mulliken, and Coulson. Unlike methods based on derivatives
of charge density (a quasi-classical concept), NBO analysis exhibits
the unifying beauty of quantum mechanical phase-matching
and superposition relationships
in all chemical phenomena.
NBO provides mutually consistent and comprehensive
analysis tools, ensuring harmonious chemical
interpretations from one property to another. The program is
uniformly implemented in leading electronic
structure packages, providing an authoritative framework for
state-of-the-art professional discourse. Widespread acceptance
of the NBO paradigm is reflected in the burgeoning number
of published applications (currently, ~1300 per year).
[Latest bugfix announcement:
November 26, 2013]
October 1, 2013: The Frank Neese group of MPI-Mülheim
announces release of NBO6-compatible Orca v. 3.0
August 16, 2013: Schrödinger Inc. announces release 2013-2 of
Jaguar v. 8.1, with NBO6 included...
July 28, 2013:
NBOPro v.6 now available...
July 27, 2013:
Marcel Patek announces a set of utilities
to assist $NBO input preparation ("Gennbo Helper") and Jmol-based
orbital visualizations ("Jmol-NBO Visualization Helper")
in NBO-based applications. Companion videos
provide useful tutorial introduction to these utilities...
May 8, 2013: J. Comp. Chem. cover feature:
"NBO 6.0, the next generation in natural bond orbital methods,...
includes link-free connectivity for
interfaces to popular electronic structure programs,
new methods of analysis, and numerous algorithmic
enhancements. The cover image is made with the NBOView 2.0
program and shows the sigma-type, 3-center/2-electron
bonding NBO of the cyclobutenyl cation that arises
from the strong overlap of the vacant valence orbital
at C1 with the C2-C3 bond. Automated multicenter bond
searches are one of the many new features of the NBO program."
[JCC 34, 1472 (2013)]
May 6, 2013: NBO6-compatible
Gaussian 09 Rev. D.01 now available, with "pop=npa6",
and related keywords...
April 11, 2013: NBO6-compatible Molpro v. 2012.1 now available...
April 8, 2013: SCM announces release of ADF2013, with NBO6 included...
March 12, 2013: "Early View" of J. Comp. Chem. article "NBO 6.0: Natural
Bond Orbital Analysis Program" (DOI: 10.1002/jcc.23266) now available...
February 4, 2013: NBO6 binaries for PC-Windows now available...
JANUARY 20, 2013: NBO6 ANNOUNCEMENT DAY...
December, 2012: GAMESS releases NBO6-compatible
source code version