Spin-orbit corrections to superexchange are calculated using the method of Moriya [T. Moriya, Phys. Rev. 120 91, (1960)] for two of the insulating parent compounds of the cuprate superconductors: (1) La2−xNdxCuO4 where the CuO6 octahedra forming each Cu-O layer are tilted in staggered fashion about an axis which depends on x and temperature; and (2) YBa2Cu3O6+x (x ∼ 0.4) where the Cu-O layers f...

A first representative of coordination polymers, built from polynuclear carboxylate bridged by mononuclear carboxylate, has been synthesised and structurally characterized. The compound [{Fe(3)O(HCOO)(6)}{Mn(HCOO)(3)(H(2)O)(3)}].3.5HCOOH crystallised in the hexagonal system (space group P6(3)), a = b = 12.369(5) A, c = 12.992(5) A, alpha = beta = 90 degrees , gamma = 120 degrees , V = 1721.4(12...

We present evidence for a near-resonant mechanism of charge transfer in short peptide nucleic acid (PNA) duplexes obtained through electrochemical, STM break junction (STM-BJ), and computational studies. A seven base pair (7-bp) PNA duplex with the sequence (TA)(3)-(XY)-(TA)(3) was studied, in which XY is a complementary nucleobase pair. The experiments showed that the heterogeneous charge tran...

The discovery of superconductivity in a $d^{9-{\delta}}$ nickelate has inspired disparate theoretical perspectives regarding the essential physics this class materials. A key issue is magnitude magnetic superexchange, which relates to whether cuprate-like high-temperature could be realized. We address question using Ni L-edge and O K-edge spectroscopy reduced trilayer $d^{9-1/3}$ La4Ni3O8 assoc...

Interference between superexchange pathways causes anisotropic magnetic interactions, leading to dimerisation and remnant quasi-one-dimensional spin chains, explaining the absence of long-range order in a 3D coordination polymer.