The goal of the project is to develop quantitative numerical methods
and computational strategies to understand the physico-chemical
properties of reversed phase liquid chromatography that lead to
selectivity and retention. Based on our initial investigation and
characterization of a realistic chromatographic system the influence
of different functionalizations of the stationary phase will be
investigated to provide further information about the selectivity of
alkyl columns. In a next step, based on the detailed atomistic
simulations which have already been carried out in our group and which
have been validated in view of experimental results, more efficient
representations of the intermolecular interactions are developed and
used in coarse grained molecular dynamics simulations. Describing
electrostatic interactions with distributed multipoles of higher order
(up to hexadecapole) has been shown in our group to lead to a
quantitative understanding of the energetics and dynamics in
condensed-phase simulations. Such extensions and generalizations will
also be pursued for the coarse grained simulations.

Reversed Phase Liquid Chromatography (RPLC) is a widely used
analytical technique in pharmaceutical separations, the food industry,
in life-science applications (peptide and protein separation), and in
the analysis of industrial polymers. Despite this importance (up to 90
\% of all analytical separations on low molecular weight samples use
RPLC) the molecular mechanisms for retention and selectivity are still
unclear. Important questions concern, for example, the understanding
of solute-solvent interactions, the influence of varying acidities of
the solvent and the role of the stationary phase in creating a
microheterogeneous environment and ultimately to unravel the origin of
selectivity of columns with different functionalizations and solvent
compositions. Such questions are ideally suited to be pursued with
computer simulations which are also validated in view of experimental
data.