Natural orbital function

Natural orbital functional vertical ionization potentials obtained from the extended Koopmans theorem. 

Natural orbital functional vibrational frequencies. Experimental vibrational frequencies from Ref. [90]. 

Goedecker S, Umrigar CJ (1998) Natural orbital functional for the many-electron problem, Phys Rev Lett, 81 866-869... 

Abstract The perfonnance of the thennodynamic fragment energy method (FEM) in the context of natural orbital functional theory (NOFT) in its PNOF5 implementation is assessed. Two test cases are considered the linear chains C H2 +2 ( = 10) and the hydrogen-bonded (FH) ... 

Keywords Natural orbital functional theory Fragment energy method APSG wavefunction... 

In the last decade, a series of functionals has been developed [1, 2] using a reconstruction proposed by Piris [3] of the two-particle reduced density matrix (2-RDM) in terms of the one-particle RDM (1-RDM). In particular, the Piris natural orbital functional 5 (PNOF5) [4, 5] has proved to... 

Finally, we want to stress out that since the GVB-PP approximation is equivalent to PNOF5 [13, 14]—one of the natural orbital functionals—the results presented in this paper can be seen as examples of performance of the PNOF5 functional in the framework of the recently proposed TD-PINO theory [26]. 

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