  The renormalization-decimation method is used to study the transmittivity of
atomic wires, with one or more side branches attached at multiple sites. The
rescaling process reduces all the branches, attached at an atomic site, to an
equivalent impurity, from which the transmission probability can be calculated
using the Lippmann-Schwinger equation. Numerical results show that the
subsequent T(E) curves, where particular attention is paid to the numbers and
locations of resonances and anti-resonances, are highly sensitive to the values
of each system's key parameters. These findings provide insight into the design
of wires with specific desired properties.
