  We synthesized the liquid crystal dimer and trimer members of a series of
flexible linear oligomers and characterized their microscopic and nanoscopic
properties using resonant soft x-ray scattering and a number of other
experimental techniques. On the microscopic scale, the twist-bend phases of the
dimer and trimer appear essentially identical. However, while the liquid
crystal dimer exhibits a temperature-dependent variation of its twist-bend
helical pitch varying from 100 - 170 {\AA} on heating, the trimer exhibits an
essentially temperature-independent pitch of 66 {\AA}, significantly shorter
than those reported for other twist-bend forming materials in the literature.
We attribute this to a specific combination of intrinsic conformational bend of
the trimer molecules and a sterically favorable intercalation of the trimers
over a commensurate fraction (two-thirds) of the molecular length. We develop a
geometric model of the twist-bend phase for these materials with the molecules
arranging into helical chain structures, and we fully determine their
respective geometric parameters.
