Hirshfeld Surface Method and Its Application in Energetic Crystals

Abstract

Understanding intermolecular interactions is fundamental to understanding the molecular stacking structures and some properties of energetic crystals, such as density, energy, mechanics, and sensitivity. The Hirshfeld surface method is a straightforward tool to reveal intermolecular interactions and nowadays has become increasingly popular in the field of energetic materials. This article highlights a wide range of applications of this method in describing intermolecular interactions including hydrogen bonding, π-stacking, halogen bonding, and lone pair−π (n−π) stacking, and molecular stacking patterns, and in predicting shear sliding characteristic and further impact sensitivity. Meanwhile, the roughness of the quantitative description of intermolecular interaction strength of the method, as a main shortcoming, is pointed out herein. Thus, this work is expected to guide the right and full use of the method. Besides, we present a perspective about using the Hirshfeld surface method to rapidly screen the molecular stacking mode and further impact sensitivity; thus, the fast screening of the two most important properties can be implemented, in combination with the existing mature energy prediction methods based on components. Thereby, a more reliable prediction procedure with an additional consideration of molecular stacking pattern will be produced, setting a basis for data-driven and crystal engineering research of energetic materials.

Energetic Cocrystallization as the Most Significant Crystal Engineering Way to Create New Energetic Materials

“…In addition, a picture of a molecular electrostatic potential surface (MEPS) is a straightforward but rough tool to understand the intermolecular interaction (Figure e). More details of the intermolecular interactions can be found in a very recent review. , …”

Exoergic pathways triggered by O/H radicals in different metallic carbohydrazide perchlorates (M2+= Mn2+, Fe2+, Co2+, Ni2+, Zn2+and Cd2+)

“…Hirshfeld surfaces and two-dimensional fingerprint plots 37,38 have been applied to understand the molecular interactions in the crystal MCPs, as shown in Fig. 2.…”

Recent advances in studying the nonnegligible role of noncovalent interactions in various types of energetic molecular crystals

“…As one of the most popular methods that can verify the location, type, and strength of intermolecular interactions through the feature of mapping functions on the surface of a particular molecule that is constructed through the weighting functions equals 0.5, the Hirshfeld surface analysis tool can also be used to investigate the critical performance through the visualization of intermolecular interactions. In 2021, Li et al 98 reviewed the application of the Hirshfeld surface in different energetic crystals. The π-π interactions were described basically based on the shape of Hirshfeld surface blocks and the location of close contacts in the 2D fingerprint maps (1.4 < d i and d e < 2.0 Å).…”