Density-functional theory and computational chemistry

计算化学（或称量子化学）是在计算机上模拟化学的一个科学领域。计算化学家可以使用量子理论和基于量子理论的计算机软件预测小分子和大分子的结构，性质和光谱，以及化学反应的方向和能量。分子中电子运动的量子理论非常复杂，但最近一种称为“密度泛函理论”（DFT）的优雅方法在简化和降低化学计算成本方面产生了巨大的影响。DFT是当今计算化学中大多数应用的基础。我们自己在过去25年里的工作在很大程度上促成了量子化学中的DFT革命。 然而，在DFT应用于弱（或“货车德瓦耳斯”）分子间相互作用，支配生物，凝聚态物质和纳米化学系统的基本和实际问题仍然存在。2005年，我们开始发展一个新的货车范德华相互作用理论，现在基本上已经完成。在今后几年中，我们将在广泛使用的新计算机软件中实现这一理论。严格的密度泛函理论应用于生物学、凝聚态物质和纳米化学问题，这将是第一次，几乎所有的化学家都有可能做到。 DFT中的其他基本剩余问题也将得到解决。其中包括：分子中的“非定域性”效应、分子中的“强”电子间关联和相对论效应（对重元素化学有重大影响）。

Computational (or "quantum") chemistry is a field of science that simulates chemistry on computers. Computational chemists can predict the structures, properties, and spectra of small and large molecules, and the directions and energetics of chemical reactions, using quantum theory and quantum-theory-based computer software. The quantum theory of the motions of electrons in molecules is very complicated, but an elegant approach called "density-functional theory" (DFT) has had enormous recent impact in simplifying and reducing the cost of chemical computations. DFT underlies most applications in computational chemistry today. Our own work over the past 25 years is largely responsible for this DFT revolution in quantum chemistry. Fundamental and practical problems remain, however, in the application of DFT to weak (or "van der Waals") intermolecular interactions that govern biological, condensed-matter, and nanochemical systems. In 2005 we began developing a novel theory of van der Waals interactions which is now essentially complete. In the next few years we will implement this theory in new computer software of wide availability. The application of rigorous density-functional theory to biological, condensed-matter, and nanochemical problems will, for the first time, be possible by virtually all chemists. Other fundamental remaining problems in DFT will also be addressed. These include: "nonlocality" effects in molecules, "strong" interelectronic correlations in molecules, and relativistic effects (which have significant impact on the chemistry of heavy elements).