title: The nature of interactions in nicotinamide crystal.
abstract: In this study, we analyze the nature of intermolecular interactions in nicotinamide complexes appearing in conformations found in the crystal structure, including many-body effects. In doing so, we employ symmetry-adapted perturbation theory based on density functional theory description of monomers, and we perform the many-body variational-perturbational interaction energy decomposition. The principal finding of this study is that the stability of nicotinamide complexes is a complicated interplay of four (large in magnitude) interaction-energy components, i.e. induction, dispersion, electrostatic and exchange repulsion. However, the last two contributions cancel each other out to a large extent. In the case of considered three-body complexes, the nonadditivity effects are found to be not important. Based on the results of topological analysis of charge densities we characterized also the properties of short H ⋯ H contact and identified it as a weak noncovalent closed shell interaction.
authors.affiliation: Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland. Electronic address: tomasz.misiaszek@pwr.wroc.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Misiaszek
authors.affiliation: Department of Inorganic Chemistry, Wrocław Medical University, Borowska 211, 50-556 Wrocław, Poland. Electronic address: zaneta.czyznikowska@gmail.com.
authors.forename: Żaneta
authors.initials: Ż
authors.lastname: Czyżnikowska
mesh_terms: D003198:Computer Simulation; D003460:Crystallization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D009536:Niacinamide / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D009536:Niacinamide
keywords: Density functional theory; Intermolecular interactions; Nicotinamide crystal; Symmetry-adapted perturbation theory