Growth analysis of sodium-potassium alloy clusters from 7 to 55 atoms through a genetic algorithm approach

Abstract

The potential energy hypersurface associated with sodium-potassium alloy clusters is explored via an enhanced genetic algorithm, where two different operators are added to the standard evolutionary procedure. Based on the recent result that the empirical Gupta many-body potential yields reasonable results for clusters with more than seven atoms, we have employed this function in the evaluation of the energies. Agglomerates from seven to the well-established 55-atom structure are studied, and their second-order energy difference and excess energies are calculated. It is found that the most stable alloys (compared to the homonuclear counterparts) are found with the proportion of sodium atoms in the range of 30 to 40%. The experimental propensity of core-shell segregation is successfully predicted by the current approach.

Application of a quantum genetic algorithm and QTAIM analysis in the study of structural and electronic properties of neutral bimetallic clusters NaxLiy (4 ≤ x + y ≤ 10)

“…A prominent class of nanomaterials is the nanoalloy which may exhibit distinct properties from the pure metal clusters and it has application in the electronics and engineering fields [2,21]. Alloy systems are important for the development of new materials with very specific properties [22][23][24][25][26]. Sodium-lithium (Na-Li) alloy has high immiscibility in liquid phase above 573 K [27][28][29].…”

“…The authors showed that the magnetic moments of the lowest energy structures with N > 17 Ti atoms (for example, 18, 25, 26, and 27 atoms) have an overall spin moment of 1 h/2π. Sodium-potassium (NaK) alloy clusters were investigated using the genetic algorithm approach by our group [26,45]. In Ref.…”

“…In Ref. [26], we analyzed the growth of NaK nanoalloys with 7 to 55 atoms through a modified genetic algorithm coupled with the empirical Gupta potential. Our results showed that all alloy structures presented sodium atoms in inner sites of the cluster while the potassium atoms were located at its surface which are in a good agreement with experimental results.…”

A New Genetic Algorithm Approach Applied to Atomic and Molecular Cluster Studies

“…In the past we proposed two new operators, namely annihilator and history operators (Guimarães et al, 2002), that demonstrated along the years (Lordeiro et al, 2003; Rodrigues et al, 2008; Silva et al, 2014a,b) to be quite efficient for determining global minima in atomic and molecular cluster studies where many local minima were present. Regarding the creation of new individuals, one can observe a broad variation among methodologies available in the literature.…”

Coordination-resolved local bond strain and 3p energy entrapment of K atomic clusters and K(1 1 0) skin

“…In the BOLS convention [15,[51][52][53][54], we choose the first and third atoms of K 44 cluster for the standard reference CN(z) for the atoms at sites of first and second atomic layers and combing the BOLS convention, we can estimated z 1 = 2.67 and z 2 = 5.12. From the relation of C(z i ) in Eq.…”