Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Structure of the first order reduced density matrix in three electron systems: A generalized Pauli constraints assisted study
Δημιουργός/Συγγραφέας:	Theophilou I. [EL] Λαθιωτάκης, Νεκτάριος N.[EN] Lathiotakis, Nektarios N. Helbig N.
Εκδότης:	American Institute of Physics Inc.
Ημερομηνία:	2018
Γλώσσα:	Αγγλικά
ISSN:	0021-9606
DOI:	10.1063/1.5020978
Άλλο:	PubMed ID: 29566524
Περίληψη:	We investigate the structure of the one-body reduced density matrix of three electron systems, i.e., doublet and quadruplet spin configurations, corresponding to the smallest interacting system with an open-shell ground state. To this end, we use configuration interaction (CI) expansions of the exact wave function in Slater determinants built from natural orbitals in a finite dimensional Hilbert space. With the exception of maximally polarized systems, the natural orbitals of spin eigenstates are generally spin dependent, i.e., the spatial parts of the up and down natural orbitals form two different sets. A measure to quantify this spin dependence is introduced and it is shown that it varies by several orders of magnitude depending on the system. We also study the ordering issue of the spin-dependent occupation numbers which has practical implications in reduced density matrix functional theory minimization schemes, when generalized Pauli constraints (GPCs) are imposed and in the form of the CI expansion in terms of the natural orbitals. Finally, we discuss the aforementioned CI expansion when there are GPCs that are almost "pinned." © 2018 Author(s).
Τίτλος πηγής δημοσίευσης:	Journal of Chemical Physics
Τόμος/Κεφάλαιο:	148
Τεύχος:	11
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Όροι και προϋποθέσεις δικαιωμάτων:	All Open Access, Green
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο