The problem of the reduction of chemistry to physics has been traditionally addressed in terms of classical structural chemistry and standard quantum mechanics. In this work, we will study the problem from the perspective of the Quantum Theory of Atoms in Molecules (QTAIM), proposed by Richard Bader in the nineties. The purpose of this article is to unveil the role of QTAIM in the inter-theoretical relations between chemistry and physics. We argue that, although the QTAIM solves two relevant obstacles to reduction by providing a rigorous definition of chemical bond and of atoms in a molecule, it appeals to concepts that are unacceptable in the quantum-mechanical context. Therefore, the QTAIM fails to provide the desired reduction. On the other hand, we will show that the QTAIM is more similar to Bohmian mechanics and that the basic elements of both theories are closely related.

El problema de la reducción entre química y física ha sido abordado principalmente a través de la mecánica cuántica estándar y la química clásica estructural. En este trabajo la estudiaremos desde la perspectiva de una teoría alternativa a la cuántica estándar, la mecánica Bohmiana y la teoría cuántica de átomos en moléculas (TCAEM) propuesta por Bader. El propósito de este artículo se centra en develar el papel que desempeña la TCAEM en las relaciones interteóricas entre química y física. Argumentaremos que si bien la TCAEM supera dos grandes obstáculos al brindar una definición rigurosa de enlace químico y átomos dentro de una molécula, la teoría hace uso de nociones clásicas incompatibles con los principios de la mecánica cuántica tradicional y por lo tanto no logra la reducción. Por otro lado mostraremos que la TCAEM guarda mayor similitud con la mecánica Bohmiana y que los elementos básicos de ambas teorías resultan afines.

The problem of the 3N dimensions of the wave function is of particular interest in the philosophy of physics. In this work, we will recall the main positions about the nature and dimensionality of the wave function and we will introduce a new perspective, coming from quantum chemistry. For this, we will bring to light the formal operations that underlie the Independent Electron Approximation. We show that the concept of the orbital is closely linked to this approximation. Therefore, its characterization as an approximation must be questioned. On this basis, we will point out how quantum chemistry can offer new arguments that contribute to the debate about the ontology of wave function.