Metal-organic frameworks (MOFs) are hybrid materials composed of inorganic nodes (clusters or metal ions) bridged by organic linkers to form three-dimensional architectures, often porous. They have been the subject of an intensive research effort for over 20 years and, taking advantage of their porosity and structural and chemical tunability, have been proposed for applications in various industrial-scale processes, such as gas storage and separation or catalysis. The majority of studies in the literature are focused on perfectly ordered, crystalline MOFs. However, inherent defects, structural disorder and large-scale flexibility are commonly found throughout this family of materials and constitute active research areas. In particular, a growing number of non-crystalline MOFs have been reported, ranging from MOF liquids to MOF gels and including a large variety of glassy states and amorphous solids produced by different physical or chemical routes. While retaining intrinsic advantages of crystals and powders, these states possess distinct physical and chemical properties (isotropy, high transparency, mechanical robustness, etc.) and allow for a greater ease of processing, making them suitable for various industrial applications, ranging from gas separation to water treatment and including reversible long-term harmful substance storage. However, the determination of the framework structure of these amorphous MOFs at the microscopic scale is experimentally difficult, with diffraction experiments only providing indirect structural information. In order to work around or alleviate this challenge, an array of computational methods coexist to model these disordered materials, with different scopes, scales and computational costs. One possible strategy consists in simulating the phase transition from a crystalline MOF to the amorphous state using molecular dynamics (MD) to mimick in silico the experimental formation routes. In prior work in our group, ab initio molecular dynamics have successfully been used to model the melting of crystalline MOFs into liquids, and generate configurations of melt-quenched glasses. 10 However, this approach has a very significant computational cost which limits its use to small systems and short time scales. Classical MD simulations, routinely used for crystalline MOFs, do not readily provide a computationally efficient alternative as they are unable to simulate bond breaking or reformation, two processes inherent to the formation of most amorphous Reactive force fields have been proposed as a trade-off between chemical accuracy and computation cost. These empirical force fields possess connection-dependent terms that enable the simulation of bond breaking and reformation. Starting with the work of Yang et al., several studies relied on reactive force fields to generate models of zeolitic imidazolate frameworks (ZIFs) glasses by melt-quenching, and computed various mechanical 14,15 and thermal properties, accessible with the larger spatial and time scales this approach can reach. However, we note that in the existing literature, the generated models have not been subjected to direct and in-depth comparison with those obtained by alternative approaches. In this work, we probe the accuracy and reliability of modeling the formation and structure of amorphous ZIFs using the ReaxFF reactive force field. We first reproduce the meltquenching procedure used in prior works, 13 highlighting several difficulties and suggesting adaptations to the scheme. We then detail the structure of the resulting glasses, and compare it to ab initio data, 10 contrasting their properties and commenting on some peculiarities of the glasses obtained with reactive force fields. Our system throughout this study will be ZIF-4, which is built up from Zn 2+ metal nodes and imidazolate (Im) organic linkers. As illustrated on Figure , its building units are organized in the crystalline state as Zn(Im) 4 tetrahedra linked by Zn-N coordinative bonds. The first discovered amorphous MOF, 17 it has since been the subject of numerous studies, both experimental and numerical, thus providing a prototypical amorphous ZIF system.