When theory came first: a review of theoretical chemical predictions ahead of experiments.

For decades, computational theoretical chemistry has provided critical insights into molecular behavior, often anticipating experimental discoveries. This review surveys twenty notable examples from the past fifteen years in which computational chemistry successfully predicted molecular structures, reaction mechanisms, and material properties before experimental confirmation. By spanning fields such as bioinorganic chemistry, materials science, catalysis, and quantum transport, these case studies illustrate how quantum chemical methods have become essential for multidisciplinary molecular sciences. The impact of theoretical predictions across disciplines shows the indispensable role of computational chemistry in guiding experiments and driving scientific discovery.