Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)




Jon Zubieta


CRYSTAL09, Solid-State DFT, Terahertz Spectroscopy, X-ray Crystallography

Subject Categories



An investigation of the structural and vibrational information of organic, hybrid organometallic and inorganic species was conducted using solid-state density functional theory (DFT). In this work the solid state DFT modeling was accomplished using the CRYSTAL09 code to simulate the geometries and vibrational modes of a variety of systems. These studies included: (1) the investigation of three polymorphs of vanadium phosphate, (2) three studies involving the use of 5-(4-pyridyl)tetrazole, and lastly (3) the crystal structure and simulation of α,α,α’,α’-tetrabromo-p-xylene. The studies involving 5-(4-pyridyl)tetrazole are comprised of (a) the comparison of a new polymorph to previously published crystallographic information of the free base 5-(4-pyridyl)tetrazole, (b) the comparison of two hydrohalide salts of 5-(4-pyridyl)tetrazole, and lastly, (c) comparing three isomorphous transition metal complexes with 5-(4-pyridyl)tetrazole as a ligand.

In the majority of these systems, with the exception of the polymorphs of vanadium phosphate, terahertz (THz) spectroscopy was used to probe the intermolecular interactions in these molecular crystals. These studies aim to increase the understanding of what effect subtle structural, compositional, or packing differences have on the vibrational normal modes, in particular in the region from 0-100 cm-1 known as the terahertz region.

It was found that subtle differences in the structure, composition, or packing could have large and varying effects on the vibrational modes, especially in the terahertz region. In particular, there are no universal trends in the shifting of vibrational frequency; however, the nature of the normal mode has the greatest effect when comparing systems that have compositional differences.


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