计算辅助分子设计的新兴领域将围绕着使计算对合成化学家有用的能力而建立,这些化学家利用基于经验的化学直觉来合成新的有用分子。这一事实带来了一个困境,因为许多现有的化学直觉都是用化学键的语言来构建的,被描绘成具有物理性质。不幸的是,有人认为,计算这些键的性质是不可能的,因为化学键不存在。对于许多计算化学界来说,债券被视为神秘的-化学世界的独角兽。这里,我们证明情况并非如此。使用相同的形式主义和概念来阐明分子中的原子,我们照亮连接它们的纽带。化学键的真实空间类似物成为分子中原子的扩展量子理论(QTAIM)中的键束。我们证明键束具有通常与化学键相关的所有特性,包括能量和电子计数。此外,债券束的特征在于许多非传统属性,包括,显著,一个边界。我们展示,从固态和分子化学中提取的例子,键束的计算特性与滋养化学直觉的特性一致。我们走得更远,然而,并表明键束为分子和材料的结构和性质提供了新的可量化的见解。
The nascent field of computationally aided molecular design will be built around the ability to make computation useful to synthetic chemists who draw on their empirically based chemical intuition to synthesize new and useful molecules. This fact poses a dilemma, as much of existing chemical intuition is framed in the language of chemical bonds, which are pictured as possessing physical properties. Unfortunately, it has been posited that calculating these bond properties is impossible because chemical bonds do not exist. For much of the computationalchemistry community, bonds are seen as mythical-the unicorns of the chemical world. Here, we show that this is not the case. Using the same formalism and concepts that illuminated the atoms in molecules, we shine light on the bonds that connect them. The real space analogue of the chemical bond becomes the bond bundle in an extended quantum theory of atoms in molecules (QTAIM). We show that bond bundles possess all the properties typically associated with chemical bonds, including an energy and electron count. In addition, bond bundles are characterized by a number of nontraditional attributes, including, significantly, a boundary. We show, with examples drawn from solid state and molecular chemistry, that the calculated properties of bond bundles are consistent with those that nourish chemical intuition. We go further, however, and show that bond bundles provide new and quantifiable insights into the structure and properties of molecules and materials.