KRONOS: Building a Plane-Wave DFT Engine From Scratch in C++20 and CUDA

Sat, 01 Aug 2026 09:00:00 +0530

Since March my nights-and-weekends repo hasn’t been a web app or a CLI tool. It’s been KRONOS — Kohn-Residual Optimized Numerics Over Silicon — an ab initio plane-wave Density Functional Theory engine written from scratch in C++20, with a CUDA backend behind a GPU abstraction layer. Feed it a crystal — lattice vectors, atom positions, a pseudopotential per element — and it computes the ground-state total energy, the electron density, Kohn-Sham eigenvalues, forces on every atom, and band structures. On the systems I’ve validated, it agrees with Quantum ESPRESSO — the reference production code in this field — to fractions of a milli-electron-volt per atom. There’s a project page with the short version; this post is the long one.

Computational-Physics on Kuldeep Pisda

KRONOS: Building a Plane-Wave DFT Engine From Scratch in C++20 and CUDA