  A versatile method for angle-resolved photoemission spectra (ARPES)
calculations is reported within the one-step model of photoemission. The
initial states are obtained from a repeated-slab calculation using the
projector-augmented wave (PAW) method. ARPES final states are constructed by
matching the repeated-slab eigenstates of positive energy with free electron
states that satisfy the time-reversed low-energy electron diffraction boundary
conditions. Nonphysical solutions of the matching equations, which do not
respect the flux conservation, are discarded. The method is applied to
surface-normal photoemission from graphene as a function of photon energy from
threshold up to 100 eV. The results are compared with independently performed
multiple scattering calculations and very good agreement is obtained, provided
that the photoemission matrix elements are computed with all-electron waves
reconstructed from the PAW pseudo-waves. However, if the pseudo-waves are used
directly, the relative intensity between $\sigma$- and $\pi$-band emission is
wrong by an order of magnitude. The graphene ARPES intensity has a strong
photon energy dependence including resonances. The normal emission spectrum
from the $\pi$-band shows a hitherto unreported, sharp resonance at a photon
energy of 31 eV. The resonance is due to a 2$D$ interband transitions and
highlights the importance of matrix element effects beyond the final state
plane-wave approximation.
