  In a previous work, we showed that unresolved excited state contaminations
provide a major source of systematic uncertainty in the calculation of the
nucleon electric dipole moment due to the QCD topological term theta. Here we
extend the calculation to the quark chromo-electric dipole moment operator
(qcEDM). We also show quantitatively the impact of the mixing of the qcEDM with
lower-dimensional operators on the lattice. Finally, we present preliminary
results from a unitary clover-on-clover calculation for the QCD topological
term.
