A possible relationship between the newly found crystal structure of CuGeO₃ and its anomalous dependence of magnetic susceptibility and lattice parameters on temperature

According to the newly found room-temperature crystal structure of CuGeO₃ (Hidaka et al., J. Phys.: Condens. Matter 9 (1997) 809), four differently distorted CuO₆ octahedra are stacked successively along the c-axis, which indicates the existence of four different nearest-neighbor exchange interactions along the c-axis, in spite of regular intervals between the Cu²⁺ on the c-axis. On the basis of this crystal structure, we propose possible answers to the questions why χ(T) does not fit the Bonner-Fisher curve, and why the lattice parameters behave anomalously when T decreases to T_sp.