Test case for perspectivism: incompatible models in quantum chemistry

Abstract

The maxim of perspectivism is that to understand the way in which knowledge is produced through models, it is necessary to consider that it is a community C with scientific knowledge K and experimental techniques E, that use a model M to represent a target system S (see Giere 2006a, 2006b; Massimi 2022; Frigg 2022). For perspectivism to understand the modeling process, the model must be associated with these variety of aspects that determine it. The discrepancy in at least some of these aspects is what could explain the sources of incompatibility (cfr. Giere 2006a). For instance, in the specific case raised by Morrison (2011; 2015) about two incompatible models of atomic nucleus, some authors (da Costa y French 2000; Bailer-Jones 2003; Teller 2001, 2011; Frish 2014; Saatsi 2014) argue that not only these models are not empirically equivalent, but they were also designed to account for different phenomena. While the liquid drop model, configuring the nucleus as an incompressible nucleus, tries to account for nuclear fission or fusion among other things, the Shell model, interpreting the particles independently, accounts for the so-called magic numbers. The objective of this article will not be to evaluate the effectiveness of criticism or defense, but to take a step back and analyze from the terms imposed by perspectivism the existence of incompatible models. We will analyze models of covalent bonds in quantum chemistry to see if these models satisfy these constraints.