Natural Bond Orbital Analysis (NBO6)
TeraChem is interfaced with the NBO6 package of Weinhold and coworkers.1 Most of the usual natural bond orbital (NBO) and natural population analyses (NPA) are supported. NBO deletions are not currently supported, nor are analyses that require matrix elements of the dipole operator.
Usage
Set the nbo keyword in the input file. The level of analysis is selected by
its value:
nbo value |
Analysis |
|---|---|
npa (or yes) |
Natural population analysis. |
full |
Full NBO/NPA analysis. |
advanced (or $nbo) |
Pass advanced NBO keywords via a $nbo group (see below). |
no |
Disabled (default). |
For advanced use, set nbo advanced and include a $nbo ... $end group in the
input file containing any advanced keywords documented in the NBO manual. A
worked example of advanced-keyword usage for CH\(_3\)NH\(_2\) ships with the
distribution under TeraChem/tests/nbo.
The verbosity of the NBO output is controlled separately by nbo_output:
nbo_output value |
Effect |
|---|---|
full / all |
Emit the complete NBO output (can be very large for nbo full). |
summary |
Keep only the summary section. |
compact / short |
Compact output. |
no / none |
Suppress NBO output. |
If nbo_output is not set, the default is all for nbo npa and summary
for the full, $nbo, and advanced modes.
NBOEXE environment variable
The NBOEXE environment variable must point to the NBO6 executable for the
interface to work. This is normally set in the SetTCVars.sh script. The
NBO6 executable is included with the TeraChem distribution and resides in
the TeraChem directory.
-
NBO6 — http://www.chem.wisc.edu/~nbo6 ↩