University of Groningen, Nijenborgh 4, Groningen, The Netherlands.
Phys Chem Chem Phys. 2011 Jul 14;13(26):12328-34. doi: 10.1039/c0cp02450c. Epub 2011 Jun 3.
The ground state electronic structure of the high-temperature (HT) and the low-temperature (LT) phases of (EDO-TTF)(2)PF(6) is investigated using the embedded cluster approach in combination with the density functional method designed to describe the strong non-dynamic electron correlation. It is found that, in the HT phase, the unpaired electron spins located on pairs of neighbouring EDO-TTF molecules are antiferromagnetically coupled along the stacking direction with the Heisenberg exchange integral J = -655 cm(-1). In the LT phase, the unpaired spins located on the cationic EDO-TTF molecules are coupled antiferromagnetically with J values strongly alternating along the stacking axis of the crystal thus rendering it diamagnetic. The parameters of the extended Hubbard model are evaluated and the conductance properties of the two phases are estimated using these parameters. It is suggested to investigate the charge and spin excitations in the two phases of (EDO-TTF)(2)PF(6) with the use of angle-resolved photoemission spectroscopy.
使用嵌入簇方法结合密度泛函方法研究了高温（HT）和低温（LT）相（EDO-TTF）（2）PF（6）的基态电子结构，该方法旨在描述强非动态电子相关。研究发现，在 HT 相中，位于相邻 EDO-TTF 分子对上的未配对电子自旋沿堆积方向呈反铁磁耦合，海森堡交换积分 J = -655 cm（-1）。在 LT 相中，位于阳离子 EDO-TTF 分子上的未配对自旋呈反铁磁耦合，J 值沿晶体堆积轴强烈交替，从而使其具有抗磁性。评估了扩展 Hubbard 模型的参数，并使用这些参数估计了两个相的电导性质。建议使用角分辨光发射光谱研究（EDO-TTF）（2）PF（6）的两个相中的电荷和自旋激发。
