Theoretical study on the long-range electron correlation and structure in soft-condensed matter

我们发展了一个半经验理论来研究长程电子关联对石墨和石墨纳米结构材料的结构和动力学的影响。近年来，对这些材料进行了许多基于密度泛函理论的计算，但这些计算甚至不能定量地预测石墨的层间结合能。其原因可能是在这种计算中没有考虑长程货车德瓦耳斯相互作用，也没有正确处理中短程电子关联。在本研究中，我们重新审视了半经验理论的早期发展，并证实了修改后的理论的有效性，通过将其应用到石墨的结合能的计算。我们还将该理论推广到单壁碳纳米管的形变能计算中，成功地预测了单壁碳纳米管的径向形变。 ...更多信息 在静水压力下的运动。由该理论预测的径向变形与实验一致，从而证实了本方法的有用性。此外，我们已经使用这个理论来阐明电子结构的修改，在静水压力下的碳纳米管的径向变形。作为相关研究，我们利用第一性原理分子动力学模拟研究了锂离子在缺陷碳纳米管上的吸附，找到了碳纳米管作为锂离子电池电极的必要条件。对CdS中各种缺陷和杂质引起的电子结构变化进行了系统的计算，并研究了p型掺杂的可能性，这在实际应用中是非常重要的。少

We have developed a semiempirical theory to investigate the effect of long-range electron correlation on the structure and dynamics of graphite and graphitic nano-structured materials. In recent years, many calculations based on the density functional theory have been performed for these materials, but these calculations are unable to predict quantitatively even the interlayer binding energy of graphite. The reason for this deficiency may be attributed to the fact that in such calculations the long-range van der Waals interaction is not taken into account at all and the electron correlations at short-and intermediate-range is not properly treated. In the present study we have revisited the semiempirical theory developed earlier and confirmed the validity of the revised theory by applying it to the calculations of the binding energy of graphite. We have also extended this theory to calculate deformation energy of single-wall carbon nanotubes and successfully predicted their radial defor … More mation under hydrostatic pressure. The radial deformations predicted by this theory are consistent with experiments, thereby confirming the usefulness of the present approach. Furthermore, we have used this theory to elucidate electronic structure modification by radial deformation in carbon nanotubes under hydrostatic pressure. These results provide a useful starting point for revealing the relation between the deformation characteristics and electronic properties, which could be useful in technological applications.As a related study, we have investigated the lithium ion adsorption on the defective carbon nanotubes using the first-principles molecular dynamics simulations and found the necessary condition to utilize carbon nanotubes as the electrode of rechargeable lithium ion battery. Systematic calculations have also been performed for the electronic structure change due to various defects and impurities in CdS and investigated the possibility of p-doping, which is quite important in practical applications. Less