A theoretical study of the NiO2 species

Abstract

The neutral, cationic and anionic NiO2 species are studied using the density-functional theory with the local spin density approximation and generalized gradient approximation methods. The most stable geometry of the NiO2 species is found to be a linear ONiO (D∞h) for the neutral and anion and to be a cyclic Ni(O2) (C2v) for the cation. The electronic structure analyses show the Ni–O bondings in the NiO2 species have both covalent and ionic character. The low-lying excited states for the ONiO and Ni(O2) isomers are calculated and used to assign the features in the photoelectronic spectrum. Our results compare well with the available experimental results.

Metal-insulator transition and electrically driven memristive characteristics of SmNiO3 thin films

“…6 It has been previously shown with the bulk form of NdNiO 3-δ that with increasing δ, T MIT shifts to higher temperature and the overall resistivity increases. 13 The similarity with results here suggests that our SNO films may lose oxygen after [14][15][16][17][18] It is possible that certain phases dominate the resistance at lower temperatures and others at higher temperatures, reminiscent of phase transition characteristics in VO x films grown on Si that also contain mixed oxide phases. 19 Note that the R-T curves demonstrate similar behavior with cycling as the in-plane measurements in LAO/SNO films.…”

“…Of the various phases observed, Ni 2 O 3 and SmO are conducting at room temperature while Sm 2 O 3 , NiO 2 (in the ground state), and NiO are insulating. [14][15][16][17][18] It is possible that certain phases dominate the resistance at lower temperatures and others at higher temperatures, reminiscent of phase transition characteristics in VO x films grown on Si that also contain mixed oxide phases. 19 Note that the R-T curves demonstrate similar behavior with cycling as the in-plane measurements in LAO/SNO films.…”

The Ni + O2reaction: A combined IR matrix isolation and theoretical study of the formation and structure of NiO2

“…1 Next, more recent density functional calculations, using several functionals, predicted that the triplet state of the peroxide isomer is more stable than the singlet. 5,[9][10][11] Nevertheless, the vibrational frequencies predicted for the triplet state are found to be in poor agreement with the experimental values measured in solid argon, 5,6 which are far better in matching the values predicted for the singlet.…”

“…With the goal of understanding in detail how dioxygen binds and further reacts at metal centres, numerous studies have been devoted to the study of the nature, physicochemical properties and reactivity of the first reaction steps of metal-dioxygen systems. The nickel oxide, NiO 2 , is an interesting model system for which both experimental [1][2][3][4][5][6][7] and theoretical [8][9][10][11][12] studies have led to contradictory results.…”

The metal coordination in Ni+(CO2)n and NiO2+(CO2)m complexes

“…The observation of two strong bands here indicates that the cluster must have a lower symmetry. NiO þ 2 has recently been calculated to have a cyclic structure with each oxygen bound to metal and with the oxygens also bound to each other [33]. If this is indeed the structure for NiO þ 2 , then the two CO 2 molecules in the m ¼ 2 cluster would have to bind opposite the oxygens in a structure with C 2v symmetry (either overall planar or with the NiO 2 plane perpendicular to the Ni-(CO 2 ) 2 plane).…”