Challenges in modeling materials properties without experimental input.

Simulations of materials behavior are an important component of materials science research, partly because measurements are indirect, requiring theoretical interpretation, and partly because often the ideal experiment simply cannot be performed (due to technological limitations). Empirical physical models used in this context often rely on parameters drawn from experiments on simpler systems, and so introduce various inaccuracies. In contrast, a quantum mechanical model can potentially offer an independent source of data more closely attuned to the complexities of the system at hand. This Perspective reviews current quantum mechanics-based materials modeling approaches and their successes and limitations, and offers a view to the future.