Low-Scaling Algorithm Applied to Twisted Transition-Metal Dichalcogenide Heterobilayers.

The method is widely used for calculating the electronic band structure of materials. The high computational cost of algorithms prohibits their application to many systems of interest. We present a periodic, low-scaling, and highly efficient algorithm that benefits from the locality of the Gaussian basis and the polarizability. The algorithm enables calculations on a MoSe/WS bilayer with 984 atoms per unit cell, in 42 h using 1536 cores. This is 4 orders of magnitude faster than a plane-wave algorithm, allowing for unprecedented computational studies of electronic excitations at the nanoscale.