The PROP (property) keyword provides a powerful and versatile
tool to perform NBO analysis of any 1e property that is available from
the host ESS program or input .47 archive file. Familiar 1e properties
include kinetic energy (PROP=KINETIC), nuclear-electron attraction
(PROP=V), Fock or Kohn-Sham operator (PROP=F),
dipole moment (PROP=DIPOLE), electron density (PROP=DM), or any other
property solely dependent on electron density. As indicated by examples
given above, the PROP keyword must include identification of the property
(e.g., PROP=KINETIC) that can be matched to .gen file input (e.g.,
$KINETIC keylist) or provided by the host ESS program through
ESS/NBO message-passing protocol.
PROP output resembles DIPOLE
or NJC output in expressing the overall property as a sum
of Lewis (L) and non-Lewis (NL) contributions, with subsidiary
correlation correction for post-SCF methods. The property is
thereby described as a sum of bond-properties (NBO contributions),
each modified by delocalization (NLMO increments or decrements) and electron-correlation
corrections to give the calculated expectation value.
PROP keyword output for the kinetic energy operator (PROP=KINETIC)
is illustrated below in sample output
for the formamide molecule (RHF/3-21G level). See the NBO 6.0 Manual,
p. B190, for additional discussion of PROP (and related DPROP) keyword usage.