# Orbital-Free DFT Correctly Models Quantum Dots When Asymptotics, Nonlocality and Nonhomogeneity Are Accounted For

## TL;DR

This paper develops a new family of nonlocal kinetic energy functionals for orbital-free DFT, enabling accurate simulations of quantum dots and clusters with highly inhomogeneous electron densities, previously a major limitation.

## Contribution

The authors introduce a universal, nonlocal kinetic energy functional that correctly models asymptotics and nonhomogeneity, extending OF-DFT's applicability to quantum dots and clusters.

## Key findings

- Achieves close to chemical accuracy in electronic energy calculations.
- Reproduces electron density within 5% of benchmark results.
- Enables orbital-free DFT to simulate highly inhomogeneous systems.

## 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 work, we address this century old problem by devising and implementing an accurate, transferable and universal family of nonlocal Kinetic Energy density functionals that feature correct asymptotics and can handle highly inhomogenous electron densities. For the first time to date, 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 demonstrates that OF-DFT is no longer limited to simulations of systems with nearly homogeneous electron density but it can venture into simulations of clusters and quantum dots with applicability to rational design of novel materials.