  Frozen natural orbitals (FNOs) are used to augment IP/EA-EOM-CCSD
calculations targeting the band gap of trans-polyacetylene and polyacene. We
show the resulting electron affinities (EAs), ionization potentials (IPs), and
extrapolated band gaps incur errors that are largely tunable to a desired
accuracy, yet require many orders of magnitude fewer core-hours as compared to
the corresponding full calculation. The relationship between various FNO
truncation schemes and (cc-pV$n$Z) basis set is also examined.
