LCAO Xα calculations of nuclear magnetic shielding in molecules

Performance of DFT for 29Si NMR Chemical Shifts of Silanes

“…7 This was formally realized by Bieger et al 8 However, up to now there have been no useful current density functionals available. Nonetheless a great success has been reached in application of DFT to magnetic shielding calculations in molecules just using an "uncoupled perturbation treatment" (UCPT), i.e., neglecting current contributions to the exchange-correlation potential and to the vector potential, as already proposed by Bieger et al 8 For an overview, see, e.g., refs 9-14. First principles NMR methods have shown a very large development of applications in all domains, with an increased interest for in situ reactions, 15,16 proteins, 17,18 zeolites, [19][20][21][22] and systems containing transition metals. 12,23,24 29 Si NMR spectra (including MAS NMR spectra for Si-containing solids) have the interesting characteristics to display large δ variations with local structure, involving the first and second shells of neighbors.…”

Study on the Aromaticity of Heterobenzenes C5H5X (X＝N, P, As, Sb, Bi) by Nucleus Independent Chemical Shifts (NICS) and Isomerization Stabilization Energies (ISE)

“…如图 8 所示, 用 不同颜色块显示不同等值面表征苯与杂苯分子的磁诱 导大小, 红色区域值越大表明由应用磁场所产生的诱导 磁场越小, 产生的磁场屏蔽越小, 向低场移动, 化学位 移增加(也可以看环内的白色区域, 其越大周围的屏蔽 越强, 高场移动, 化学位移减小) [3,4,45] . 对苯可分析得到 …”

Theoretical and experimental 13C and 15N NMR investigation of guanylhydrazones in solution

“…The first DFT application in NMR did not take into account the so-called gauge problem. 16 The groups of Malkin and Ziegler have published a series of pioneering papers on the calculation of NMR properties using this methodology. 17 -19 In those studies, the shielding tensor is a sum of two contributions: the diamagnetic tensor d and the paramagnetic tensor p .…”