Predicting the products and mechanisms of chemical reactions using density-functional theory

化学的核心是研究物质是如何通过化学反应转变的。化学的理论方法使用数学和计算技术来描述化学反应和分子性质，当实验研究不切实际或实验数据难以解释时，理论方法尤其重要。在理论化学的范围内，没有什么任务比反应预测问题更基本：给定的试剂选择是否在特定环境中反应，如果是，产物是什么？此外，重要的是要了解化学反应机理：反应物和产物之间的分子变化序列，它定义了化学反应如何发生。对反应机理的了解使人们能够预测反应速度，并有助于设计新的化学工艺，使浪费的副反应最少或最大限度地提高反应速度。

At its core, chemistry is the study of how substances are transformed by chemical reactions. Theoretical approaches to chemistry use mathematical and computational techniques to describe chemical reactions and molecular properties and are particularly important when experimental studies are impractical or experimental data are difficult to interpret. Within the purview of theoretical chemistry, no task is more fundamental than the reaction prediction problem: does a given choice of reagents react in a particular environment and, if so, what is the product? Furthermore, it is important to know the chemical reaction mechanism: the sequence of molecular changes between reactants and products that defines how the chemical reaction occurs. Knowledge of the reaction mechanism allows one to predict reaction rates and facilitates the design of new chemical processes that minimize wasteful side-reactions or maximize the reaction rate.