Document Type

Thesis

Degree

Master of Science (MS)

Department

Physics

First Advisor's Name

Xuewen Wang

First Advisor's Title

Committee Chair

Second Advisor's Name

Richard Bone

Third Advisor's Name

H Rudolf Fiebig

Date of Defense

6-14-2012

Abstract

This research develops a new method for understanding the properties of materials. The new method was applied to alkali metals to examine how well it can predict the Wigner-Seitz radius, rs. Pseudo-potentials for the individual atoms were generated and utilized to obtain the interaction energy within these metals.

The system involves 4 coulombic charges; two of them are the result of the neutral atom (one valence electron and one positive core charge for alkali atoms) and the other two are background charges of equal and opposite amount. This coulombic interaction will behave differently depending on the element that composes the system. There are four groups of energy for this system. One of them has the appearance of the Jellium model, which is solved with Density Functional Theory. From the other three groups, one of them will alter the minimum of the Jellium model for different elements in the system. This group is partially calculated with the help of Ewald summation. This calculation exemplifies that bcc is favored since it is lower in energy than fcc, which is in agreement with experiments for alkali metals. The correction to this energy will be due to the core electrons' interaction with a uniform negative charge background. This new method will also be beneficial to calculate the ground state energy of clusters by introducing surface boundaries in the system.

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