The Fierce Morphological Battle of Silver Nanoparticles: How Irregularities, Vacancies and Defects Tip the Crossing Sizes.

Solving the morphological complexity of nanomaterials such as silver nanoparticles, at the one-atom level, is a prerequisite to reach a rational design of their properties. To date, structural measurements in ultra-high vacuum of silver nanoparticles remain uninterpreted. The narrow competition between octahedra and decahedra evolves in morphological statistics in the range 309-923 atoms, whereas the most stable icosahedra appear as a minority. To solve this debate, an extensive ab initio investigation of silver nanoparticles is presented in the range 18-1654 atoms (500 nanoparticles). Originally, we interpret measurements, thanks to the inclusion of defects. A very narrow competition is highlighted between defective truncated octahedra and Marks-decahedra, both dominating defective icosahedra in number but not in stability, and the experimental assumption suggesting that the presence of all symmetries is due to kinetic trapping is supported. Highly accurate computational conditions are mandatory to predict crossing sizes between structures, within one-atom precision. This exigence results from the usual stability descriptor. Imagine solving the morphological debate of silver nanoparticles without an accuracy of 10 - 5 eV. at - 1 in cohesion energy is illusory. The provided ab initio database opens promising perspectives to train machine-learning approaches aiming to examine morphological battles at larger size.