Atoms in molecules
Atoms in molecules
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DOI：
10.1039/9781847553317-00143
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发表时间：
2000-12
期刊：
影响因子：
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通讯作者：
A. Hinchliffe;P. Popelier;F. M. Aicken;Sean E O'Brien
中科院分区：
文献类型：
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作者：
A. Hinchliffe;P. Popelier;F. M. Aicken;Sean E O'Brien
1.1什么是AIM？分子中的原子理论（AIM）是一种解释性理论，旨在从现代高分辨率电子密度中恢复化学洞察力。[1]这些密度可能来自实验，也可能来自从头算波函数。AIM定义了化学的两个重要基石：原子和键。有一个需要这样的理论，鉴于化学的洞察力和目前接受和教导，一方面，和巨大的不断增长的机构（高分辨率）晶体学和从头算数据，另一方面之间的差距不断扩大。事实上，大多数化学家仍然按照20世纪的刘易斯模型（如八隅体规则）、20世纪30年代的海特勒-伦敦-鲍林价键模型（如共振）或20世纪60年代的亨德-马利肯分子轨道（如马利肯电荷）来思考。当然，许多这些早期的概念已被仔细审查，其局限性是有据可查的，但一个完整的，连贯的和一致的理论，以弥合差距之间的现代解决方案的薛定谔方程和化学的见解仍然是难以捉摸的。然而，实现这一目标的一个很好的候选人是AIM。这个理论经常被误认为是另一种原子布居分析，而不是一个广泛而深刻的理论植根于量子力学。作为一种新的范式，尽管它已被列为最近一本针对大学生的化学键教科书的重要组成部分，但它的接受速度很慢。理论界把大部分注意力集中在核运动的能量及其导数上，即。如果人们接受本征值和本征函数与本征值问题（如薛定谔方程）的解一样，那么为什么电子密度不享有与能量相同的地位呢？毕竟，电子密度r是直接从波函数导出的，它是一个本征函数，而能量实际上是一个本征值。这种不平衡的观点被AIM的发展和应用所纠正，AIM是一种认识和揭示隐藏在电子密度及其衍生函数中的丰富信息的理论。
1.1 What Is AIM?±The theory of``Atoms in Molecules''(AIM) is an interpretative theory which aims to recover chemical insight from modern highresolution electron densities. 1 These densities may be of experimental origin or derived from ab initio wave functions. AIM defines two important cornerstones of chemistry: the atom and the bond. There is a need for such a theory in view of the widening gap between chemical insight and currently accepted and taught, on one hand, and the vast ever-growing body of (high-resolution) crystallographic and ab initio data, on the other. Indeed, most chemists still think in terms of the Lewis model of the 1900s (eg octet rule), the Heitler-London-Pauling Valence Bond model of the 1930s (eg resonance), or the Hund-Mulliken Molecular Orbital of the 1960s (eg Mulliken charges). Of course many of these early concepts have been scrutinised and their limitations are well documented but a complete, coherent and consistent theory to bridge the gap between modern solutions of the SchroÈdinger equation and chemical insight is still elusive. However, an excellent candidate to fulfil that purpose is AIM. This theory is often mistaken to be another atomic population analysis, rather than an extensive and profound theory rooted in quantum mechanics. 2 Being a novel paradigm3 it has gained slow acceptance although it has been incorporated as a vital part of a recent textbook on the chemical bond4 aimed at undergraduates. The theoretical community has focused most of its attention on the energy and its derivatives with respect to nuclear motion, ie. forces, force constants, etc. If one accepts that eigenvalues and eigenfunctions are on a par as solutions of an eigenvalue problem such as the SchroÈdinger equation, then why is it that the electron density does not enjoy the same status as the energy? After all the electron density r is immediately derived from the wave function, which is an eigenfunction, and the energy is in fact an eigenvalue. This imbalanced view is corrected by the development and application of AIM, a theory that recognises and reveals the wealth of information hidden in the electron density and its derived functions.