Date of Award

2016-01-01

Degree Name

Master of Science

Department

Physics

Advisor(s)

Tunna Baruah

Abstract

A computational study on the structure and electronic properties of the VSc2N@C68 molecule was carried out using the density functional theory. This molecule is based on the recent report on the synThesis of the VSc2N@C80 and V2ScN@C80 fullerenes. The Sc3N@C68 is also a stable endohedral fullerene that has a cage with fuse pentagonal rings. The doping by a V atom changes the structure as well as the spin state of the Sc3N@C68 from S=0 to S=1 state. Since the C68 has 6332 isomers, we have carried out an extensive search for the lowest energy structure of the C68 in several anionic structures: -2, -4, -6. The first screening of the anionic structures was done using PM6 methods. The lowest 300 isomers from this set was chosen, the endohedral fullerene was built with three different orientations of the endohedral unit and further optimized. The final 13 lowest energy structures were optimized at the DFT level. This extensive search showed that the lowest energy isomer of VSc2N@C80 differs from that of the Sc3N@C68 structure. The lowest energy isomer has three fused pentagons on the carbon cage. The isomers are found to be distinct with an energy difference of 0.46 eV between the two lowest isomers. The presence of the V leads to a S=1 state. The energetics show that the VSc2N@C68 can also be a good electron acceptor and is chemically stable. The calculated absorption spectra can help in characterization of the molecule in experiment.

Language

en

Provenance

Received from ProQuest

File Size

44 pages

File Format

application/pdf

Rights Holder

Surendra Bhatta

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Physics Commons

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