English

On the Quantum Theory of Molecules: Rigour, Idealization, and Uncertainty

Quantum Physics 2026-04-29 v2 History and Philosophy of Physics

Abstract

Philosophers have claimed that: (a) Born-Oppenheimer approximation methods for solving molecular Schr\"odinger equations violate the Heisenberg uncertainty relations; therefore, (b) `quantum chemistry' is not fully quantum; and (c) therefore chemistry does not reduce to physics. This paper analyses the reasoning behind Born-Oppenheimer methods and shows that they are internally consistent and fully quantum mechanical, contrary to (a)-(c). Our analysis addresses important issues of mathematical rigour, physical idealization, reduction, and classicality in the quantum theory of molecules, and we propose an agenda for the philosophy of quantum chemistry more grounded in scientific practice.

Keywords

Cite

@article{arxiv.2411.01942,
  title  = {On the Quantum Theory of Molecules: Rigour, Idealization, and Uncertainty},
  author = {Nick Huggett and James Ladyman and Karim P. Y. Thébault},
  journal= {arXiv preprint arXiv:2411.01942},
  year   = {2026}
}