  Alternation in various properties of n-alkanes (CnH2n+2) as a function of
carbon content (n) is termed odd-even effect. Here, we report a comprehensive
molecular dynamics simulation study on n-alkane systems carried out with n
ranging between 3 (propane) and 8 (octane), examining the odd-even effect in
melting point, density, intramolecular conformational ordering, translational
and rotational motion. We observe an odd-even alternation in these properties,
but with heptane (n = 7) exhibiting anomalous behavior for all except
conformational ordering. Our simulations also show the presence of odd-even
behavior in rotational and translational dynamics, below and above the melting
point, respectively. The results highlight the role of both molecular shape and
the variation in density and their interplay in the origins of the odd-even
effect.
