We employ noncollinear density functional theory to show that the low-spin state of Mn3 in a model of the oxygen-evolving complex of photosystem II avoids frustrated spin coupling by adopting a noncollinear arrangement of spins, thereby lowering the energy by 7 kcal/mol. The high-spin state also has noncollinear spins. The optimum self-consistent field solutions for this multinuclear oxomanganese complex correspond to states that cannot be described by the unrestricted Slater determinants used in Kohn-Sham collinear density functional methods. This kind of spin coupling can be important in many open-shell systems, and the conventional collinear spin interpretation of chemical bonding in such systems should be viewed with caution. © 2011 American Chemical Society.
Noncollinear spins provide a self-consistent treatment of the low-spin state of a biomimetic oxomanganese synthetic trimer inspired by the oxygen evolving complex of photosystem II / Luo, Sijie; Rivalta, Ivan; Batista, Victor; Truhlar, Donald G.*. - In: THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS. - ISSN 1948-7185. - STAMPA. - 2:20(2011), pp. 2629-2633. [10.1021/jz201077n]
Noncollinear spins provide a self-consistent treatment of the low-spin state of a biomimetic oxomanganese synthetic trimer inspired by the oxygen evolving complex of photosystem II
Rivalta, Ivan;
2011
Abstract
We employ noncollinear density functional theory to show that the low-spin state of Mn3 in a model of the oxygen-evolving complex of photosystem II avoids frustrated spin coupling by adopting a noncollinear arrangement of spins, thereby lowering the energy by 7 kcal/mol. The high-spin state also has noncollinear spins. The optimum self-consistent field solutions for this multinuclear oxomanganese complex correspond to states that cannot be described by the unrestricted Slater determinants used in Kohn-Sham collinear density functional methods. This kind of spin coupling can be important in many open-shell systems, and the conventional collinear spin interpretation of chemical bonding in such systems should be viewed with caution. © 2011 American Chemical Society.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.