Combining strengths of DFT and wave functions: The short-range DFT-DMRG method

Hedegård, E. D. (Oplægsholder)

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Electronic structures with large static and dynamical correlation effects pose a formidable challenge in modern quantum chemistry. Static correlation can be recovered using a complete active space (CAS) method where all possible configurations are considered for a pre-selected space of orbitals and electrons. However, these methods are very restricted in terms of the choice of the active space, especially if dynamical correlation is also to be included. The latter is typically done in subsequent steps, using e.g. perturbation theory.

The density matrix renormalization group (DMRG) method has been able to extend the active space considerably compared to traditional CAS methods. For the dynamical correlation problem, a very promising new approach is to couple wave function and density functional theories, using range-separation.
Here we describe a range-separated short-range DFT method with a long-range wave function based on DMRG (DMRG-srDFT).

We present a few pilot applications for small systems such as dissociation of the water and the di-nitrogen molecules. We further
study the DMRG and DMRG-srDFT in terms of one- and two-orbital entropies and mutual information correlation plots (see figure below).
Periode1. jun. 20156. jun. 2015
BegivenhedstitelRecent advances in electronic structure theory. null
PlaceringNanjing, Kina