  The development of kinetic energy (KE) functionals is one of the current
challenges in density functional theory (DFT). The Yukawa non-local KE
functionals [Phys. Rev. B 103, 155127 (2021)] have been shown to describe
accurately the Lindhard response of the homogeneous electron gas (HEG) directly
in the real space, without any step in the reciprocal space. However, the
Yukawa kernel employs an exponential function which cannot be efficiently
represented in conventional Gaussian-based quantum chemistry codes. Here, we
present an expansion of the Yukawa kernel in Gaussian functions. We show that
for the HEG this expansion is independent of the electronic density, and that
for general finite systems the accuracy can be easily tuned. Finally, we
present results for atomistic sodium clusters of different sizes, showing that
simple Yukawa functionals can give superior accuracy as compared to semilocal
functionals.
