One of the products of the reduction of LaNiO3 is LaNiO2, containing monovalent nickel. This valence state of nickel has scarcely been observed in mineral compounds. X-ray data from powder samples and extended X-ray absorption fine structure studies (EXAFS) allow one to define a tetragonal structure with lanthanum at the centre of a prism composed of oxygen atoms having a square base and nickel in the centre of the square. The Ni—O distance (nearest neighbour) was found to be 1.983 Å for this monovalent nickel.
No takes yet. Share an insight, caveat, or question.
Levitz et al. (1983) studied this question.