References:
 

         M.Velegrakis and Ch.Lüder, "Formation and stability of singly and doubly charged MgArN Clusters",

         Chem. Phys. Lett., 223, 139 (1994)

 

         Ch. Lüder, D. Prekas and M.Velegrakis, “Ion-size effects in the growth sequences of  metal-ion-doped noble gas clusters”,

         Laser Chemistry, 17, 109 (1997)

 

         D. Prekas,  Ch. Lüder and M. Velegrakis, ” Structural transitions in metal-ion-doped noble gas clusters: Experiments and molecular dynamics simulations”,

         J. Chem. Phys. 108, 4450 (1998)

 

         G. E. Froudakis,  S. C. Farantos and M. Velegrakis, “ Mass Spectra and Theoretical Modeling of Li+Nen, Li+Arn and Li+Krn Clusters”,

         Chem. Phys.,  258, 13, 2000

 

         M. Velegrakis, “Stability, structure and optical properties of metal ion-doped noble gas clusters”,

         in : Advances in metal and semiconductor clusters, Chapter 7, Vol. V, ed. M.A. Duncan (JAI Press, Greenwich), June 2001


 

Hard Sphere Packing Model

Structural transitions in metal-doped noble gas clusters

Using time-of-flight (TOF) mass spectrometry, the stability and the structure of metal ion-doped noble gas clusters M+Xn (M=metal atom and X=noble gas atom) is studied.

The observed change in magic number series is explained by a simple hard sphere packing model,  showing that the observed new magic numbers are consistent with a cluster growth sequence based on a capped square antiprism (CSA) 11-atomic cluster. Additionally, molecular dynamics simulations using pairwise additive Lennard-Jones potentials are performed. The results of these calculations verify the structural results from the hard sphere model and furthermore explain the structural transition as a function of cluster size.

 

Typical TOF spectra  of metal ion-doped noble gas clusters of the type M+Xn. The most stable clusters are indicated by the total number of atoms N=n+1.

High-symmetry Polyhedra formed from two twisted polygons each of them shaped from n/2 atoms

 

R*=RM/RX=

 

0.225

 

Tetrahedron

n=4

 

0.414

 

Octahedron antiprism

n=8

 

n+1 =

5

7

0.645

 

Square antiprism

n=8

Capped Square antiprism

n=8+2

11

Pentagonal antiprism

n=10

Icosahedron (closed)

n=10+2

0.902

 

13

Hexagonal antiprism

n=12

Capped Hexagonal antiprism

n=12+2

1.17

15

Schlegel Diagrams explaining  cluster growth sequences and magic numbers

 

ICOSAHEDRON

 

CSA

 

Text Box: Number of Bonds
Text Box: Number of Bonds