  We analyze structural and conformational properties in a simulated
bead-spring model of a non-entangled, supercooled polymer melt. We explore the
statics of the model via various structure factors, involving not only the
monomers, but also the center of mass (CM). We find that the conformation of
the chains and the CM-CM structure factor, which is well described by a
recently proposed approximation [Krakoviack et al., Europhys. Lett. 58, 53
(2002)], remain essentially unchanged on cooling toward the critical glass
transition temperature of mode-coupling theory. Spatial correlations between
monomers on different chains, however, depend on temperature, albeit smoothly.
This implies that the glassy behavior of our model cannot result from static
intra-chain or CM-CM correlations. It must be related to inter-chain
correlations at the monomer level. Additionally, we study the dependence of
inter-chain correlation functions on the position of the monomer along the
chain backbone. We find that this site-dependence can be well accounted for by
a theory based on the polymer reference interaction site model (PRISM). We also
analyze triple correlations by means of the three-monomer structure factors for
the melt and for the chains. These structure factors are compared with the
convolution approximation that factorizes them into a product of two-monomer
structure factors. For the chains this factorization works very well,
indicating that chain connectivity does not introduce special triple
correlations in our model. For the melt deviations are more pronounced,
particularly at wave vectors close to the maximum of the static structure
factor.
