The global minimum of Ag₃₀: a prolate spheroidal structure predicted using a genetic algorithm with incomplete local optimizations at the DFT level

Abstract

Genetic algorithms have been widely used to explore global minimums of atomic clusters, and their incorporation with ab initio calculations (including Density Functional Theory, DFT, methods) as local optimization approaches...

Reactivity of cationic silver clusters with O2: a probe of interplay between clusters’ geometric and electronic structures

“…The structure search of silver clusters was conducted using our newly encoded genetic algorithm program with an incomplete local optimization strategy, 33 in which all optimization processes and energy calculations were carried out using the Gaussian09 program. 43 Briefly, we used a module to generate random structures including, a space-free motif, a close packing motif, a simple cubic packing motif, a cage motif, a solid sphere motif, a ring motif and other user-defined motifs.…”

“…The efficiency and reliability of methods have been previously shown in searching the structure of Ag 30 and other representative clusters. 33 The initial structural candidates of Ag n O 2 + reaction products were generated by randomly putting O 2 around all possible adsorption sites of obtained lowest-lying structures of Ag n + , and various adsorption patterns including O-atop and O–O doubly connected geometries in their doublet or quartet state were considered. The complete and incomplete optimizations in this study were at the PBE level with the def2-SVP basis set for Ag and def2-TZVP basis sets for O.…”

“…Reactions between Ag n − and O 2 used as supplemental probes for the electronic properties of anionic silver clusters according to a scenario in which one electron transfers from the anionic silver moiety to the adsorbed O 2 in formed complexes. 28–33 There are drastic changes in the reactivity for sizes of Ag n − containing 8 and 20 free electrons, which implies the formation of electron shells like those in an atom. 30,31 The interplay between the geometric and electronic structures was discussed in sizes containing 14 and 30 free electrons.…”

“…30,31 The interplay between the geometric and electronic structures was discussed in sizes containing 14 and 30 free electrons. 30,33 A recent study combining reaction experiments and theoretical calculations showed the remarkable stability of Ag 17 − due to its closed electronic as well as geometric shells, 32 and a single congener doping atom can result in the rearrangement of the geometry of Ag 17 − and significantly change its electronic properties and reactivity. 34…”

Electronic Structure of Heteronuclear Cerium-Platinum Clusters

“…An exhaustive computational search for the clusters in a variety of geometries and spins states was conducted. Since these species had four or fewer atoms, all structural permutations were done manually, as opposed to employing the more sophisticated approaches (e.g., genetic or evolutionary algorithms; , simulated annealing, or other methods that sample wide structure spaces) demonstrated in recent studies on larger metal or metal oxide clusters, several recent examples of which are included in the references. − All physically reasonable spin states were computed, although again, we note that we rely on the computational results for a qualitative description. If various spin states are predicted to be very close-lying (e.g., <0.1 eV separation), we would be reluctant to assert which state is truly lower-lying.…”