behavior is due to the synergistic combination of the well-defined organic-inorganic nature of 1 and its anisotropic layered structure that gives rise to two different types of robust excitons (interlayer and intralayer). The assignment of the observed optical features to the excitons was done based on the fundamental principles of molecular excitons extensively described in the last 50 years in books, [2] reviews [3a-c] and research papers; [3d-l] and supported by complex transmission, reflectance, and photoluminescence (PL) spectroscopy with polarization and time resolution.Polozkov et al. [4] made a comment to dispute our assignment of the optical features to excitons, based on the results of electronic structure calculations carried out using the generalized gradient approximation Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional on a simplified 2D periodic model of a single layer of 1 (Figure 1). Despite the severe oversimplification of the actual system in the model and the known limited accuracy of pure exchange-correlation functionals for describing excitations in molecular systems, [5] the authors obtained a nearly quantitative agreement between the computed and experimentally observed features in the absorption spectrum. Given the intrinsic limitation of the time-dependent density functional theory (DFT) method to single-particle excitations and its fundamental inability to describe excitonic states, these results motivated the authors to question our interpretation of the experimental data and propose an alternative model that is solely based on a single-particle approximation. We do not agree with the new proposal and identify a number of critical flaws in the logics underlying the comment. Below we provide extensive argumentation supporting our viewpoint.First of all, we believe that the coincidence between a computed parameter and an experimental one cannot be used as a justified ground for the construction of a physical or chemical hypothesis without a critical assessment of the potential limitations related to the accuracy of both the model and the method employed in the calculations. The method accuracy in this context can be better viewed as the precision of the calculation -that is, how well a particular quantum chemical method describes the electronic structure and basic parameters of chemical systems; and it is commonly assessed against a back-drop of a desired well-defined outcome. [6] Modern quantum-chemical methodologies are suitable for resolving ground-state chemical phenomena with <4 kJ mol −1 absolute accuracy, which is often referred to as the "chemical accuracy". [6c] However, when dealing with such complex systems as the metal-organic frameworks, this high This is a response to a comment on the interpretation of the origin of the nonlinear changes of optical properties of van der Waals' metal-organic frameworks (MOFs). The concerns are addressed by clarifying potential pitfalls in density functional theory (DFT) simulations, careful analysis of prior literature, and...