TY  - INPR
A1  - Lindner, Joachim O.
A1  - Sultangaleeva, Karina
A1  - Röhr, Merle I. S.
A1  - Mitric, Roland
T1  - metaFALCON: A program package for automatic sampling of conical intersection seams using multistate metadynamics
T2  - Journal of Chemical Theory and Computation
N2  - The multistate metadynamics for automatic exploration of conical intersection seams and systematic location of minimum energy crossing points in molecular systems and its implementation into the software package metaFALCON is presented. Based on a locally modified energy gap between two Born–Oppenheimer electronic states as a collective variable, multistate metadynamics trajectories are driven toward an intersection point starting from an arbitrary ground state geometry and are subsequently forced to explore the conical intersection seam landscape. For this purpose, an additional collective variable capable of distinguishing structures within the seam needs to be defined and an additional bias is introduced into the off-diagonal elements of an extended (multistate) electronic Hamiltonian. We demonstrate the performance of the algorithm on the examples of the 1,3-butadiene, benzene, and 9H-adenine molecules, where multiple minimum energy crossing points could be systematically located using the Wiener number or Cremer–Pople parameters as collective variables. Finally, with the example of 9H-adenine, we show that the multistate metadynamics potential can be used to obtain a global picture of a conical intersection seam. Our method can be straightforwardly connected with any ab initio or semiempirical electronic structure theory that provides energies and gradients of the respective electronic states and can serve for systematic elucidation of the role of conical intersections in the photophysics and photochemistry of complex molecular systems, thus complementing nonadiabatic dynamics simulations.
KW  - Computational Chemistry
KW  - Metadynamics
KW  - Hydrogen
KW  - Hydrocarbons
KW  - Chemical Structure
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199258
UR  - https://doi.org/10.1021/acs.jctc.9b00029
N1  - This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Chemical Theory and Computation, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see Journal of Chemical Theory and Computation 2019, 15, 6, 3450-3460. https://doi.org/10.1021/acs.jctc.9b00029.
ER  - 
TY  - THES
A1  - Lindner, Joachim Oliver
T1  - Multistate Metadynamics with Electronic Collective Variables
T1  - Mehrzustandsmetadynamik mit Elektronischen Kollektiven Variablen
N2  - The aim of this thesis was to develop new automatic enhanced sampling methods by extending the idea of Parrinello’s metadynamics to multistate problems and by introducing new quantum-mechanical electronic collective variables. These methods open up a rich perspective for applications to the photophysical processes in complex molecular systems, which play a major role in many natural processes such as vision and photosynthesis, but also in the development of new materials for organic electronics, whose function depends on specific electronic properties such as biradicalicity.
N2  - Das Ziel dieser Arbeit war die Entwicklung neuer automatisierter Methoden für beschleunigtes Sampling molekularer Strukturen durch eine Erweiterung von Parrinellos Metadynamik auf Mehrzustandsprobleme und die Verwendung neuer quantenmechanischer elektronischer kollektiver Variablen. Die entwickelten Methoden bieten einen breiten Anwendungsspielraum im Bereich der photophysikalischen Prozesse komplexer molekularer Systeme, welchen in vielen natürlichen Vorgängen wie beispielsweise dem Sehen und der Photosynthese, aber auch in der Entwicklung neuer Materialien für die organische Elektronik eine Schlüsselrolle zukommt. Die Eigenschaften solcher funktioneller Materialien werden durch spezifische elektronische Eigenschaften wie dem Biradikalcharakter bestimmt.
KW  - Theoretische Chemie
KW  - Fotochemie
KW  - Fotophysik
KW  - Biradikal
KW  - Molekulardynamik
KW  - Conical Intersections
KW  - Konische Durchschneidung
KW  - Metadynamics
KW  - Metadynamik
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191638
ER  -