A density-functional theory for a polyatomic system is applied to gas-
liquid nucleation in n-butane and n-heptane, employing an interaction
site model and the rotational isomeric state approximation. Effects of
chain length and flexibility on equilibrium properties and nucleation
are discussed. It is shown that the n-alkane systems cannot be well a
pproximated by a system with the spherically symmetric Lennard-Jones p
otential, giving a nucleation rate scaled by the classical rate smalle
r by six orders of magnitude. (C) 1998 American Institute of Physics.
[S0021-9606(98)50542-9]