When it comes to studying solid-state systems on a microscopic scale, electronic structure calculations based on density-functional theory (DFT) are among the most popular. Currently, the cost of computational time limits these calculations to periodic systems of about a thousand atoms, which is often too small to describe amorphous and disordered materials, or composite structures, such as thin-film devices.

Writing in *Physical Review B*, Alexander Thiess, at the Jülich Research Center in Germany, and colleagues report an algorithm that allows tens of thousands of processors to efficiently communicate while performing density-functional calculations. As a result, they are able to calculate the electronic properties of systems ten times larger than what was previously possible with similar methods. To demonstrate their new code, they put $65,536$ processors to work at solving the matrix equation of a system of more than $16,000$ atoms.

This is one of the most precise DFT-based codes available, and unlike algorithms where increasing the size of the system demands an exponential growth in processing power, in Thiess *et al.*’s approach it scales linearly with system size (at least in the limit that a large number of processors are already being used). This tool will enable researchers to study new problems in large-scale systems, such as the effect of long-range interactions between particles, which is not easily calculated with existing codes. – *Hari Dahal*