International Workshop on 'New challenges in Reduced Density Matrix Functional Theory: Symmetries, time-evolution and entanglement'
Separation of dynamic and nondynamic correlationEduard Matito
Ikerbasque, Basque Science Foundation, Spain
Coauthor(s) : Eloy Ramos-Cordoba[1,2,3], Mauricio Rodríguez-Mayorga[1,2,4], Mireia Via-Nadal[1,2], Pedro Salvador
 Donostia International Physics Center, Euskadi, Spain,  IKERBASQUE, Basque Foundation for Science, Bilbao, Spain,  University of California, Berkeley. United States,  Univ. Girona, Catalonia, Spain
The account of electron correlation and its efficient separation into dynamic and nondynamic parts plays a key role in the development of computational methods such as hybrid, range- separated  or local methods . In this work we split the correlated part of the pair density into two correlation functions that account for nondynamic and dynamic correlation effects . These functions are used in a two-electron model, giving rise to dynamic and nondynamic cor- relation functions that (i) depend only on natural orbitals and their occupancies, (ii) can be straightforwardly decomposed into orbital contributions, and (iii) admit a local form  (see Fig. 1). Finally, using the same strategy we present a separation of the Coulomb Hole into dy- namic and nondynamic correlation. The long-range part of the dynamic-correlation hole can be used to identify dispersion interactions as confirmed by perturbation analysis . These expressions can aid in the development of density matrix functional theory (DMFT), density functional theory (DFT) and the development of local hybrid methods.
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