  Comparing observational abundance features with nucleosynthesis predictions
of stellar evolution or explosion simulations can scrutinize two aspects: (a)
the conditions in the astrophysical production site and (b) the quality of the
nuclear physics input utilized. We test the abundance features of r-process
nucleosynthesis calculations for the dynamical ejecta of neutron star merger
simulations based on three different nuclear mass models: The Finite Range
Droplet Model (FRDM), the (quenched version of the) Extended Thomas Fermi Model
with Strutinsky Integral (ETFSI-Q), and the Hartree-Fock-Bogoliubov (HFB) mass
model. We make use of corresponding fission barrier heights and compare the
impact of four different fission fragment distribution models on the final
r-process abundance distribution. In particular, we explore the abundance
distribution in the second r-process peak and the rare-earth sub-peak as a
function of mass models and fission fragment distributions, as well as the
origin of a shift in the third r-process peak position. The latter has been
noticed in a number of merger nucleosynthesis predictions. We show that the
shift occurs during the r-process freeze-out when neutron captures and
{\beta}-decays compete and an (n,{\gamma})-({\gamma},n) equilibrium is not
maintained anymore. During this phase neutrons originate mainly from fission of
material above A = 240. We also investigate the role of {\beta}-decay
half-lives from recent theoretical advances, which lead either to a smaller
amount of fissioning nuclei during freeze-out or a faster (and thus earlier)
release of fission neutrons, which can (partially) prevent this shift and has
an impact on the second and rare-earth peak as well.
