NBO

NBO
	Appendix A. Keyword Reference

NBO calls a modified version of the NBO 3.0 created by E. D. Glendening, A. E. Reed, J. E. Carpenter, and F. Weinhold. This program performs the analysis of a many-electron molecular wavefunction in terms of localized electron-pair 'bonding' units. Use NBO=n to control the amount of output and the types of analysis to be performed. Plain NBO is equivalent to NBO=2. For ROHF and C.I. (explicit or implicit), energetic analysis will not be performed.

NBO=0

Perform natural bond orbital (NBO) analysis but suppress all output. Results and the NBO orbitals will be available in the .vis file (unless NOVIS). The NBO orbitals may be visualized in AGUI along the same lines as the canonical MOs.

NBO=1

Perform natural population analysis (NPA) in addition to the basic NBO analsys. The results and NBO orbitals will be available in the .vis file as with NBO=0

NBO=2

Perform NPA and NBO but also include an analysis of the direction and bending modes for each hybrid orbital (BEND) and energy perturbation analysis (E2PERT). Also add the NBO summary (NBOSUM) table.

NBO=3

Perform a study of natural localized molecular orbitals (NLMO) in addition to the usual NPA and NBO analysis. The molecular dipole moment (DIPOLE) will be analyzed according to both the NBO and NLMO orbitals. The NLMO orbitals will also be present (unless NOVIS) in addition to the NBO orbitals. These orbitals may be visualized in AGUI.

NBO=4

Same as NBO=3 but also print the NLMO to MO transformation matrix. The NBO and NLMO orbital coefficients will also be printed in the output file. Note that this particular feature is not currently implemented for SPARSE calculations..

NBO≥5

Same as NBO=4 but also print additional details about the NBO search. (Note: this can be output can become prohibatively large for large molecules.)

Abbreviation:

none

Requires: