The past decades have seen density functional theory (DFT) evolve from a rising star in computational quantum chemistry to one of its major players. This Theme Issue, which comes half a century after the publication of the Hohenberg-Kohn theorems that laid the foundations of modern DFT, reviews progress and challenges in present-day DFT research. Rather than trying to be comprehensive, this The...

The Fast Fourier Transform (FFT) is the most efficiently known way to compute the Discrete Fourier Transform (DFT) of an arbitrary n-length signal, and has a computational complexity of O(n log n). If the DFT ~ X of the signal ~x has only k non-zero coefficients (where k < n), can we do better? In [1], we addressed this question and presented a novel FFAST (Fast Fourier Aliasing-based Sparse Tr...

The Fast Fourier Transform (FFT) is the most efficiently known way to compute the Discrete Fourier Transform (DFT) of an arbitrary n-length signal, and has a computational complexity of O(n log n)1. If the DFT ~ X of the signal ~x has only k non-zero coefficients (where k < n), can we do better? In [1], we presented a novel FFAST (Fast Fourier Aliasing-based Sparse Transform) algorithm that cle...

Entanglement distinguishes quantum mechanics from classical physics and as such is the core resource in most applications of quantum information science. In previous demonstrations, entangled photons have allowed fundamental tests of quantum mechanics, provided secure communication protocols, enabled computations using algorithms no classical computer could perform efficiently, and provided imp...

The fabrication of a non-doped red organic light-emitting device (OLED) has been developed using naturally occurring curcumin as an emissive layer of OLED. In this research, the electroluminescent spectrum (EL) of curcumin as a donor-acceptor-donor (D-A-D) chromophore was obtained at wavelength of 612 nm. Also, the maximum external quantum efficiencies (EQE) for this device was measured and fou...

studies of the magnetization of fe2o3@pt nanoparticles at room temperature showed that there is superparamagnetic contribution with high saturation magnetization about 12.35(emu/g), and soft ferromagnetic contribution with narrow coercive field about 58(oe). in this paper we fitted the hystersis loop of sample with brillouin function that demonstrating existence of superparamagnetic phase. tota...

Density functional theory (DFT) codes are commonly treated as a "black box" in high-throughput screening of materials, with users opting for the default values input parameters. Often, non-experts may not sufficiently consider effect these parameters on prediction quality. In this work, we attempt to identify robust set related smearing and tetrahedron methods that return numerically accurate e...

Density functional theory (DFT) is now the most commonly used method of electronic structure calculation in both condensed matter physics and quantum chemistry, thanks in part to the focus it has received over the first 50 years of the Sanibel Symposium. We present a short history, and review fourteen short and easy but important lessons about nonrelativistic DFT, with some partiality but with ...