  We extend to initial ground states with zero spin density m = 0 the
expressions provided by the pseudofermion dynamical theory (PDT) for the
finite-energy one- and two-electron spectral-weight distributions of a
one-dimensional (1D) correlated metal with on-site particle-particle repulsion.
The spectral-function expressions derived in this paper were used in recent
successful and detailed theoretical studies of the finite-energy singular
features in photoemission of the organic compound
tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) metallic phase. Our
studies take into account spectral contributions from types of microscopic
processes that do not occur for finite values of the spin density. Expressions
for the spectral functions in the vicinity of the singular border lines which
also appear in the TTF- TCNQ spectral-weight distribution are derived. In
addition, the PDT expressions are generalized for electronic densities in the
vicinity of half filling. Further details on the processes involved in the
applications to TTF-TCNQ are reported. Our results are useful for the further
understanding of the unusual spectral properties observed in low-dimensional
organic metals and also provide expressions for the one- and two-atom spectral
functions of a correlated quantum system of ultracold fermionic atoms in a 1D
optical lattice with on-site two-atom repulsion.
