Perspective: Fifty years of density-functional theory in chemical physics

TLDR

Kohn‑Sham density‑functional theory, introduced in the mid‑1960s, has become the dominant electronic‑structure method because of its simple framework and computational efficiency, and since the mid‑1980s its exchange‑correlation advances have made it competitive with wave‑function approaches, yet today it faces increasing demands for accuracy that threaten to erode its distinctiveness. The author hopes to preserve the Kohn‑Sham philosophical, theoretical, and computational framework. The Perspective reviews the history, core concepts, and current status of KS‑DFT in chemical physics and proposes directions for its future development.

Abstract

Since its formal inception in 1964-1965, Kohn-Sham density-functional theory (KS-DFT) has become the most popular electronic structure method in computational physics and chemistry. Its popularity stems from its beautifully simple conceptual framework and computational elegance. The rise of KS-DFT in chemical physics began in earnest in the mid 1980s, when crucial developments in its exchange-correlation term gave the theory predictive power competitive with well-developed wave-function methods. Today KS-DFT finds itself under increasing pressure to deliver higher and higher accuracy and to adapt to ever more challenging problems. If we are not mindful, however, these pressures may submerge the theory in the wave-function sea. KS-DFT might be lost. I am hopeful the Kohn-Sham philosophical, theoretical, and computational framework can be preserved. This Perspective outlines the history, basic concepts, and present status of KS-DFT in chemical physics, and offers suggestions for its future development.