The layout of this thesis is as follows: In Chapter 2 we present the theoretical
background relevant to our study, namely NMR, Density Functional
Theory (DFT), PAW and GIPAW. We also report the performed computational
tests that validate our implementation. In Chapter 3 we first give the
experimentally determined structural properties of cholesterol crystals for all
known phases and compare our theoretical results with these reports. In this
chapter we also examine the adequacy of classical force field calculations in
structure determination through comparisons with both ab initio results and
experiment. In Chapter 4 we report our results for NMR spectrum of all
known phases and comment on the accuracy of our calculations. Factors affecting
the ab initio NMR calculations are investigated in detail, such as the
impact of structural optimization and exchange-correlation functionals. A
systematic error observed in GIPAW calculations is also discussed and a possible
correction is proposed. We further test the validity of the introduced
correction using the results of spectral editing experiments. Finally using
all the information gathered, we perform peak assignment for the observed
NMR spectra. We also compare the NMR spectrum obtained from molecules
and crystals to draw conclusions on the intermolecular interactions present
in cholesterol crystals.
