N-electron Valence State Perturbation Theory
In quantum chemistry, n-electron valence state perturbation theory (NEVPT) is a perturbative treatment applicable to multireference CASCI-type wavefunctions. It can be considered as a generalization of the well-known second-order Møller-Plesset perturbation theory to multireference Complete Active Space cases. The theory is directly integrated into the quantum chemistry package DALTON.
The research performed into the development of this theory lead to various implementations. The theory here presented refers to the deployment for the Single-State NEVPT, where the perturbative correction is applied to a single electronic state. Research implementations has been also developed for Quasi-Degenerate cases, where a set of electronic states undergo the perturbative correction at the same time, allowing interaction among themselves. The theory development makes use of the quasi-degenerate formalism by Lindgren and the Hamiltonian multipartitioning technique from Zaitsevskii and Malrieu.
Read more about N-electron Valence State Perturbation Theory: Theory, Properties, See Also
Famous quotes containing the words state and/or theory:
“The concept of a mental state is primarily the concept of a state of the person apt for bringing about a certain sort of behaviour.”
—David Malet Armstrong (b. 1926)
“Many people have an oversimplified picture of bonding that could be called the “epoxy” theory of relationships...if you don’t get properly “glued” to your babies at exactly the right time, which only occurs very soon after birth, then you will have missed your chance.”
—Pamela Patrick Novotny (20th century)