论文标题
螺旋有机和无机聚合物
Helical Organic and Inorganic Polymers
论文作者
论文摘要
尽管是合成塑料和生物分子的主食，但在与分子平等基础上的电子相关方法中，几乎没有使用高斯基 - 基础{\ it It tib} {\ IT i it i i i it i it It timio}进行螺旋聚合物研究。本文介绍了{\ it Ab intio}二阶多体绿色功能[MBGF（2）]方法，使用螺钉轴对象型旋转的高斯高斯透明型缓慢的基础函数的无限旋转聚合物的非对抗，频率依赖的dyson自我能力。与高斯 - 基础 - 基础密度功能功能理论一起，用于能量，分析原子力，转换力和螺旋角力，它可以计算无限螺旋聚合物的相关能量，结构和振动频率，结构和振动频率，在无限的螺旋聚合物中平稳地汇聚在相应的oligomermorigomers上。这些方法可以处理具有无限翻译时期的不可估量的结构，并且很难通过任何其他方法来表征，就像可相称的结构一样有效。 We apply these methods to polyethylene ($2/1$ helix), polyacetylene (Peierls' system), and polytetrafluoroethylene ($13/6$ helix) to establish the quantitative accuracy of MBGF(2)/cc-pVDZ in simulating their (angle-resolved) ultraviolet photoelectron spectra, and of B3LYP/cc-pVDZ or 6-31G **在重现其结构，红外和拉曼带位置，声子分散以及（连贯和不一致的）无弹性中子中子散射光谱。然后，我们预测了无限型氮或氧链的相同特性，并在环境条件下讨论它们可能的亚稳态存在。其中包括平面曲折多氮存（n $ _2 $）$ _ x $（PEIERLS的系统），$ 11/3 $ - 螺旋 - 螺旋同位素聚会（NH）$ _ x $，$ 9/4 $ - helical isotactic iSotactic Polyfluoroazane（nf）高能密度材料。
Despite being a staple of synthetic plastics and biomolecules, helical polymers are scarcely studied with Gaussian-basis-set {\it ab initio} electron-correlated methods on an equal footing with molecules. This article introduces an {\it ab initio} second-order many-body Green's-function [MBGF(2)] method with nondiagonal, frequency-dependent Dyson self-energy for infinite helical polymers using screw-axis-symmetry-adapted Gaussian-spherical-harmonics basis functions. Together with the Gaussian-basis-set density-functional theory for energies, analytical atomic forces, translational-period force, and helical-angle force, it can compute correlated energy, quasiparticle energy bands, structures, and vibrational frequencies of an infinite helical polymer, which smoothly converge at the corresponding oligomer results. These methods can handle incommensurable structures, which have an infinite translational period and are hard to characterize by any other method, just as efficiently as commensurable structures. We apply these methods to polyethylene ($2/1$ helix), polyacetylene (Peierls' system), and polytetrafluoroethylene ($13/6$ helix) to establish the quantitative accuracy of MBGF(2)/cc-pVDZ in simulating their (angle-resolved) ultraviolet photoelectron spectra, and of B3LYP/cc-pVDZ or 6-31G** in reproducing their structures, infrared and Raman band positions, phonon dispersions, and (coherent and incoherent) inelastic neutron scattering spectra. We then predict the same properties for infinitely catenated chains of nitrogen or oxygen and discuss their possible metastable existence under ambient conditions. They include planar zigzag polyazene (N$_2$)$_x$ (Peierls' system), $11/3$-helical isotactic polyazane (NH)$_x$, $9/4$-helical isotactic polyfluoroazane (NF)$_x$, and $7/2$-helical polyoxane (O)$_x$ as potential high-energy-density materials.
