5 papers
Spectroscopic photorelaxation signatures in pyrazine from nonadiabatic dynamics simulations with coupled cluster theory
Sara Angelico, Eirik F. Kjønstad, Yi-Ping Chang +3
Despite extensive theoretical and experimental efforts, the mechanisms underlying the ultrafast relaxation of pyrazine after photoexcitation remain challenging to disentangle. Rece…
eT 2.0: An efficient open-source molecular electronic structure program
Sarai Dery Folkestad, Eirik F. Kjønstad, Alexander C. Paul +34
The eT program is an open-source electronic structure program with emphasis on performance and modularity. As its name suggests, the program features extensive coupled cluster capa…
Similarity Constrained CC2 for Efficient Coupled Cluster Nonadiabatic Dynamics
Leo Stoll, Sara Angelico, Eirik F. Kjønstad +1
Despite their high accuracy, standard coupled cluster models cannot be used for nonadiabatic molecular dynamics simulations because they yield unphysical complex excitation energie…
Generalized coupled cluster theory for ground and excited state intersections
Federico Rossi, Eirik F. Kjønstad, Sara Angelico +1
Coupled cluster theory in the standard formulation is unable to correctly describe conical intersections among states of the same symmetry. This limitation has restricted the pract…
Determining minimum energy conical intersections by enveloping the seam: exploring ground and excited state intersections in coupled cluster theory
Sara Angelico, Eirik F. Kjønstad, Henrik Koch
Minimum energy conical intersections can be used to rationalize photochemical processes. In this Letter, we examine an algorithm to locate these structures that does not require th…