The electronic structures, the equilibrium geometries and finite temperature properties of Na_n (n=39-55)

Abstract

Density-functional theory has been applied to investigate systematics of sodium clusters Na_n in the size range of n= 39-55. A clear evolutionary trend in the growth of their ground-state geometries emerges. The clusters at the beginning of the series (n=39-43) are symmetric and have partial icosahedral (two-shell) structure. The growth then goes through a series of disordered clusters (n=44-52) where the icosahedral core is lost. However, for n>52 a three shell icosahedral structure emerges. This change in the nature of the geometry is abrupt. In addition, density-functional molecular dynamics has been used to calculate the specific heat curves for the representative sizes n= 43, 45, 48 and 52. These results along with already available thermodynamic calculations for n= 40, 50, and 55 enable us to carry out a detailed comparison of the heat capacity curves with their respective geometries for the entire series. Our results clearly bring out strong correlation between the evolution of the geometries and the nature of the shape of the heat capacities. The results also firmly establish the size-sensitive nature of the heat capacities in sodium clusters.

This paper contains of 8 pages and 13 figures

References in corpus (10)

• Global Optimization by Basin-Hopping and the Lowest Energy Structures of Lennard-Jones Clusters Containing up to 110 Atoms
• Structure and properties of small sodium clusters
• Magic Numbers for Classical Lennard-Jones Cluster Heat Capacities
• Negative heat capacity of sodium clusters
• Orbital-Free Molecular Dynamics Simulations of Melting in Na8 and Na20: Melting in Steps
• Magic Melters' Have Geometrical Origin
• First principles investigation of finite-temperature behavior in small sodium clusters
• On the premelting features in sodium clusters
• Thermodynamics of Na_8 and Na_{20} clusters studied with ab-initio electronic structure methods
• Effect of geometric and electronic structures on the finite temperature behavior of Na${}_{58}$, Na${}_{57}$, and Na${}_{55}$ clusters

Cited by in corpus (1)

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