Zobrazeno 1 - 10
of 86
pro vyhledávání: '"Kjønstad, Eirik F."'
Autor:
Kjønstad, Eirik F., Fajen, O. Jonathan, Paul, Alexander C., Angelico, Sara, Mayer, Dennis, Gühr, Markus, Wolf, Thomas J. A., Martínez, Todd J., Koch, Henrik
The fate of thymine upon excitation by ultraviolet radiation has been the subject of intense debate over the past three decades. Today, it is widely believed that its ultrafast excited state decay stems from a radiationless transition from the bright
Externí odkaz:
http://arxiv.org/abs/2403.01045
Coupled cluster theory is one of the most accurate electronic structure methods for predicting ground and excited state chemistry. However, the presence of numerical artifacts at electronic degeneracies, such as complex energies, has made it difficul
Externí odkaz:
http://arxiv.org/abs/2403.01007
Autor:
Kjønstad, Eirik F., Koch, Henrik
We present an efficient implementation of analytical non-adiabatic derivative coupling elements for the coupled cluster singles and doubles model. The derivative coupling elements are evaluated in a biorthonormal formulation in which the nuclear deri
Externí odkaz:
http://arxiv.org/abs/2301.13264
We present an efficient implementation of ground and excited state CCSD gradients based on Cholesky-decomposed electron repulsion integrals. Cholesky decomposition, like density-fitting, is an inner projection method, and thus similar implementation
Externí odkaz:
http://arxiv.org/abs/2202.02019
Autor:
Hait, Diptarka, Lahana, Dean, Fajen, O. Jonathan, Paz, Amiel S. P., Unzueta, Pablo A., Rana, Bhaskar, Lu, Lixin, Wang, Yuanheng, Kjønstad, Eirik F., Koch, Henrik, Martínez, Todd J.
Publikováno v:
Journal of Chemical Physics; 6/28/2024, Vol. 160 Issue 24, p1-14, 14p
Autor:
Kjønstad, Eirik F., Koch, Henrik
In coupled cluster methods, the electronic states are biorthonormal in the sense that the left states are orthonormal to the right states. Here we present an extension of this formalism to a left and right total molecular wave function. Starting from
Externí odkaz:
http://arxiv.org/abs/2007.06668
Multilevel CC2 and CCSD in reduced orbital spaces: electronic excitations in large molecular systems
We present efficient implementations of the multilevel CC2 (MLCC2) and multilevel CCSD (MLCCSD) models. As the system size increases, MLCC2 and MLCCSD exhibit the scaling of the lower level coupled cluster model. In order to treat large systems, we c
Externí odkaz:
http://arxiv.org/abs/2006.05226
Publikováno v:
Phys. Rev. X 10, 041043, 2020
We present an ab initio correlated approach to study molecules that interact strongly with quantum fields in an optical cavity. Quantum electrodynamics coupled cluster theory provides a non-perturbative description of cavity-induced effects in ground
Externí odkaz:
http://arxiv.org/abs/2005.04477
We introduce a multimodel approach to solve coupled cluster equations, employing a quasi Newton algorithm for the ground state and an Olsen algorithm for the excited states. In these algorithms, both of which can be viewed as Newton algorithms, the J
Externí odkaz:
http://arxiv.org/abs/2004.07773
Autor:
Folkestad, Sarai D., Kjønstad, Eirik F., Myhre, Rolf H., Andersen, Josefine H., Balbi, Alice, Coriani, Sonia, Giovannini, Tommaso, Goletto, Linda, Haugland, Tor S., Hutcheson, Anders, Høyvik, Ida-Marie, Moitra, Torsha, Paul, Alexander C., Scavino, Marco, Skeidsvoll, Andreas S., Tveten, Åsmund H., Koch, Henrik
The eT program is an open source electronic structure package with emphasis on coupled cluster and multilevel methods. It includes efficient spin adapted implementations of ground and excited singlet states, as well as equation of motion oscillator s
Externí odkaz:
http://arxiv.org/abs/2002.05631