... Polyhedron. Volume 29, Issue 15, 14 October 2010, Pages 2976–2984. ... J as defined by the spin Hamiltonian H = −2JS 1 S 2 (S 1 = S 2 = 5/2) is strongly related to the Fe–O–Fe bond angle, and the J value of linear Fe–O–Fe was found larger than that of bent one [15] and [16]. ...