At a
conical intersection point, the plane spanned by the
gradient difference vector
(
)
and the
gradient of the interstate
coupling vector
(
):
where
and
are the configuration interaction eigenvectors (i.e., the excited and ground-state
adiabatic wavefunctions) in a
conical intersection problem,
is the
conical intersection Hamiltonian,
represents the nuclear configuration vector of the system, and thus
is a unit vector in the direction of vector
.
and
are the energies of the lower and upper states, respectively.
Note:
The branching plane is also referred to as the
g-
h plane. Inspection of
and
provides information on the geometrical deformation imposed on an
excited state molecular entity immediately after decay at a
conical intersection. Consequently, these vectors provide information on the
ground-state species that will be formed after the decay.
Source:
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 309
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
