Top Curr Chem (2016) 368: 445–476
DOI: 10.1007/128_2015_631
# Springer International Publishing Switzerland 2015
Published online: 21 April 2015
Description of Conical Intersections
with Density Functional Methods
Miquel Huix-Rotllant, Alexander Nikiforov, Walter Thiel,
and Michael Filatov
Abstract Conical intersections are perhaps the most significant mechanistic features of chemical reactions occurring through excited states. By providing funnels
for efficient non-adiabatic population transfer, conical intersections govern the
branching ratio of products of such reactions, similar to what the transition states
do for ground-state reactivity. In this regard, intersections between the ground and
the lowest excited states play a special role, and the correct description of the
potential energy surfaces in their vicinity is crucial for understanding the mechanism and dynamics of excited-state reactions. The methods of density functional
theory, such as time-dependent density functional theory, are widely used to
describe the excited states of large molecules. However, are these methods suitable
for describing the conical intersections or do they lead to artifacts and, consequently, to erroneous description of reaction dynamics? Here we address the first
part of this question and analyze the ability of several density functional
approaches, including the linear-response time-dependent approach as well as the
spin-flip and ensemble formalisms, to provide the correct description of conical
intersections and the potential energy surfaces in their vicinity. It is demonstrated
that the commonly used linear-response time-dependent theory does not yield a
proper description of these features and that one should instead use alternative
computational approaches.
M. Huix-Rotllant
Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-LaueStr. 7, 60438 Frankfurt am Main, Germany
A. Nikiforov and W. Thiel
Max-Planck-Institut fu ¨r Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mu ¨lheim an der
Ruhr, Germany
M. Filatov (*)
Institut fu ¨r Physikalische und Theoretische Chemie, Universita ¨t Bonn, Beringstr. 4, 53115
Bonn, Germany
e-mail: mike.filatov@gmail.com
DOI: 10.1007/128_2015_631
# Springer International Publishing Switzerland 2015
Published online: 21 April 2015
Description of Conical Intersections
with Density Functional Methods
Miquel Huix-Rotllant, Alexander Nikiforov, Walter Thiel,
and Michael Filatov
Abstract Conical intersections are perhaps the most significant mechanistic features of chemical reactions occurring through excited states. By providing funnels
for efficient non-adiabatic population transfer, conical intersections govern the
branching ratio of products of such reactions, similar to what the transition states
do for ground-state reactivity. In this regard, intersections between the ground and
the lowest excited states play a special role, and the correct description of the
potential energy surfaces in their vicinity is crucial for understanding the mechanism and dynamics of excited-state reactions. The methods of density functional
theory, such as time-dependent density functional theory, are widely used to
describe the excited states of large molecules. However, are these methods suitable
for describing the conical intersections or do they lead to artifacts and, consequently, to erroneous description of reaction dynamics? Here we address the first
part of this question and analyze the ability of several density functional
approaches, including the linear-response time-dependent approach as well as the
spin-flip and ensemble formalisms, to provide the correct description of conical
intersections and the potential energy surfaces in their vicinity. It is demonstrated
that the commonly used linear-response time-dependent theory does not yield a
proper description of these features and that one should instead use alternative
computational approaches.
M. Huix-Rotllant
Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-LaueStr. 7, 60438 Frankfurt am Main, Germany
A. Nikiforov and W. Thiel
Max-Planck-Institut fu ¨r Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mu ¨lheim an der
Ruhr, Germany
M. Filatov (*)
Institut fu ¨r Physikalische und Theoretische Chemie, Universita ¨t Bonn, Beringstr. 4, 53115
Bonn, Germany
e-mail: mike.filatov@gmail.com