Abstract
is one of only a few ternary oxides which are known to form in the orthorhombic Pmmnstructure. The layered 
structure, favored for application as a 
-insertion electrode, is found in many other alkali transition metal oxides. We find that the the strong antiferromagnetic interactions between 
ions contribute to the stabilization of the orthorhombic structure. Using first‐principles pseudopotential calculations, we find that doping with 
, 
, 
, 
, 
, 
, 
, 
, 
, and 
helps stabilize the layered structure over the orthorhombic structure. ©1999 The Electrochemical Society