"The nature of the chemical bond is the problem at the heart of all chemistry."  -Bryce Crawford

At its core, the NBO program requires only minimal information from a host electronic structure system (ESS) program: the 1e density matrix (in unspecified AO basis) and the corresponding overlap matrix and angular symmetry labels (s,p,d,...) of the AOs. Neither the spatial forms of AOs (whether Gaussian-type, Slater-type, etc.) nor any other type of structural or energetic information is required for basic NAO/NBO/NLMO/NRT tasks.

However, many additional NBO analysis options (PLOT, 2nd-order energetic analysis, $DEL-deletions, NMR properties analysis, etc.) become available as additional information is provided from the ESS host. In many cases, the ESS/NBO information flow is passive and one-way (e.g., spatial information for PLOT output, or the converged Fock/Kohn-Sham matrix for energetic analysis, etc.), and non-interactive "stand-alone" GenNBO functionality suffices. However, more powerful ESS/NBO applications (such as $DEL-deletions or NEDA) require full two-way interactivity, which has heretofore required binary linking. That technical hurdle has now been removed in NBO6.

NBO6 is based on a message-passing protocol that allows free-standing ESS and NBO6 binaries to communicate and perform complex ESS/NBO6 "cooperative binary-pair" tasks. The NBO Team can provide the necessary snippets of template fortran freeware (and other technical assistance, as required) that allow your ESS program to begin interacting with an accessible NBO6 program.

The virtual ESS/NBO6 interface can be as simple or complex as you wish, depending on the message types you choose to implement (one- or two-way, services or requests for services, etc.). In principle, virtually any ESS can now implement the powerful $DEL-deletions, NEDA, NCS, and other interactive options that were previously accessible only in linked Gaussian/NBO5 or GAMESS/NBO5 configurations. In addition, many other types of NBO-based CAS/CC/CI methods and specialized property analyses can now be implemented to enhance (or show off) the unique capabilities of your ESS.

Contact Eric Glendening (eric.glendening@indstate.edu) for further information on building NBO6-compatibility into your ESS program.

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Program & Distributor




ADF: Scientific Computing & Modelling N.V.
NOW AVAILABLE! ADF2013 with NBO6 included... (more)


DEMON2K: deMon Developers (demon-software.com)
[includes interface to write valid NBO archive files as input for stand-alone GenNBO programs (including that provided with NBO6)]


FIREFLY/PC-GAMESS: Alex Granovsky (Moscow State Univ.)
[includes NBO5 (requires TCI/NBO password); NBO6-compatible upgrade expected]


GAMESS(U.S.): Mark Gordon (Iowa State Univ.)
NOW AVAILABLE! NBO6-compatible source version offers fully interactive GAMESS/NBO6 functionality... <(more)>


GAUSSIAN: Gaussian, Inc.
NOW AVAILABLE! NBO6-compatible G09, Rev. D.01 offers full G09/NBO6 binary-to-binary interactivity... (more)

[Source G09, Rev. C can also be compiled and linked with source NBO6 (replacing "NBO 3.1" of the native distribution) for old-style G09/NBO6 linked interactivity... (more)]


JAGUAR: Schrödinger, Inc.
NOW AVAILABLE! NBO6 included in standard Jaguar 8.1 distribution... (more)


MOLCAS: Molcas.org (Univ. Lund)
[includes older NBO3-level code (NPA only)]


MOLPRO: H.-J. Werner (Univ. Stuttgart)
NOW AVAILABLE! NBO6-compatible Molpro v. 2012.1 allows source or binary level installation of NBO 6.0... (more)


NWCHEM: Pacific Northwest National Laboratories
[includes interface to NBO5; NBO6-compatible upgrade expected]


ORCA: Frank Neese (MPI-Mülheim)
NOW AVAILABLE! NBO6-compatible Orca v. 3.0 offers GenNBO6-type binary-to-binary functionality... (more)


PQS: Parallel Quantum Solutions
[includes NBO5; NBO6-compatible upgrade expected]


PSI4: PSI4 Project (Va. Tech., Ga. Tech.)
[includes interface to write valid NBO archive files as input for stand-alone GenNBO programs (including that provided with NBO6)]


Q-CHEM: Q-Chem, Inc.

NOW AVAILABLE! NBO6 interface (as well as installed NBO 5.0 program) now included in standard Q-Chem v. 4.2 distribution... ( more)


SPARTAN: Wavefunction, Inc.
[includes older NBO3-level code (NPA only)]


TERACHEM: PetaChem, LLC
NOW AVAILABLE! NBO6 included in standard TeraChem distribution... ( User Guide, p. 16)


TURBOMOLE: Turbomole GmbH
[includes older NBO3-level code (NPA only)]



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