Stability of Antiferromagnetism against Pairwise Bonding

Ground-state wave functions, including correlations, are investigated for antiferromagnets with few nearest neighbors. The possibility of forming a stronger bond with one of the neighbors than with the others, through lattice distortion, is examined. The relevance to the low-temperature state of ${\mathrm{V}}_2$ ${\mathrm{O}}_3$ is discussed.