The crystalline solid state is unique among the classes of materials available in the materials property space for combining ordered structure and emerging properties such as optical, mechanical, and magnetic that are directly related to the disposition and interaction between the structural units (atoms, molecules, ions) in the lattice. Over the past few decades, research on crystalline states has flourished, including research communities in organic solid-state chemistry, crystal engineering, and extended, dynamic, and adaptive crystal structures. The research endeavors in this field capitalize on the possibility of controlling the properties of crystalline solids based on their nascent anisotropy inherent to the order in their structures and being able to control and predict such properties based on experimental and data-driven approaches. Specifically, molecular crystals, solids consisting of individual molecules sitting on ordered lattice sites are emerging materials for applications ranging from pharmaceuticals, energetic materials, battery electrodes, to organic electronics, to more exotic environments such as those existing on cryogenic conditions of moons, comets, or exoplanets. This cluster of research directions draws on the basic understanding of the softness of intermolecular interactions, such as hydrogen or halogen bonding, and their utility in designing specific properties of molecular materials. A unique aspect of the ordered solid state is that it is amenable to direct analysis with diffraction methods that include both classical approaches like X-ray diffractions, and contemporary methods such as a combination of light, pressure, temperature, and other specific environments with techniques such as steady-state and time-resolved X-ray and electron diffraction methods. The ability of these materials to diffract is not typical for other materials. It provides the most direct information on different levels of structural hierarchy and sets the basis for correlation, explanation, and prediction of their properties down to atomic scale resolution. The availability of databases with diligently collected and precise information on these opens up an additional avenue for informed analysis, correlation, and application.

The proposed symposium aims to capture recent advances in a venue that brings together investigators from a range of communities―pharmaceuticals, energetic materials, pharmaceuticals, organic electronics, solid mechanics, and any others interested in crystalline materials. The symposium will focus attention on three key issues that we believe can define the field and determine future directions of solid-state research. These issues are: the nature of the intermolecular interactions that determine the optical, transport, magnetic and mechanical properties; the methods to determine, assess and predict the properties of molecular materials; and the limits of performance under normal and extreme conditions, and the most appropriate uses of molecular materials to explore their full potential. In the workshop, we intend to address the following questions:
● What is the nature of the intermolecular interactions determining the optical, transport, magnetic and mechanical properties?
● How can the properties of the molecular materials be determined, assessed, and predicted?
● What are the limits of performance under normal and extreme conditions, and what are the most appropriate uses of molecular materials that explore their full potential?

An open conversation between the leaders of various fundamental and applied aspects is crucial to capitalize on the properties of crystalline materials. The development of new experimental tools, such as electron and neutron diffraction, significantly alleviates the long-standing limitations of having sufficient crystals of sufficient size and quality, and the capabilities of the time-resolved methods to probe structural dynamics can capture spatial and time domain information simultaneously. This information, combined with advances in theory and computation, now makes it possible to address these issues comprehensively, thoroughly, and meaningfully.

The proposed symposium is designed to be a platform for interdisciplinary collaboration, inviting both experimentalists and computational scientists from diverse fields (chemistry, physics, engineering) whose research focuses on the study of structural and dynamic aspects of crystalline materials. The symposium aims to be inclusive and interactive, fostering discussion among participants from different backgrounds and bridging the gap that currently exists between various communities, particularly those with science and engineering training. The goal is to provide a constructive, cooperative, supportive, and creative environment for the exchange of ideas, promoting a dialogue on the unique aspects of crystals that qualify them as next-generation energy-harvesting, sustainable, pharmaceutical, and environmental materials.