Argentophillic interactions in argentum chalcogenides: First principles calculations and topological analysis of electron density.

The plasticity of Ag S and Ag Se crystals important for applications is associated mainly with AgAg metallophilic bonds, which are related to van der Waals interactions and therefore are not directed. This is demonstrated by the first principles DFT M06 LCAO calculations of Ag X (X = S, Se) crystals (periodic model) and hypothetical molecules X Ag (X = S, Se; n = 1, 2, 4) in gas phase (molecular model). A topological analysis of the calculated electron density, was performed both for periodic and molecular models of Ag X (X = S, Se).