Orbital-free density functional theory correctly models quantum dots when asymptotics, nonlocality, and nonhomogeneity are accounted for

Abstract

Million-atom quantum simulations are in principle feasible with orbital-free density functional theory (OF-DFT) because the algorithms only require simple functional minimizations with respect to the electron density function. In this context, OF-DFT has been useful for simulations of warm dense matter, plasma, cold metals, and alloys. Unfortunately, systems as important as quantum dots and clusters (having highly inhomogeneous electron densities) still fall outside OF-DFT's range of applicability. In this Rapid Communication, we make considerable progress in addressing this century old problem by devising and implementing an accurate, transferable, and universal family of nonlocal noninteracting kinetic energy density functionals that feature correct asymptotics and can handle highly inhomogeneous electron densities. We show that OF-DFT achieves close to chemical accuracy for the electronic energy and reproduces the electron density to about 5% of the benchmark for semiconductor quantum dots and metal clusters. Therefore, this work shows that OF-DFT can reliably simulate systems with highly inhomogeneous electron density, such as clusters and quantum dots, with applicability to the rational design of materials.