  The ground X1{\Sigma}+ state potential energy curve (PEC) and dipole moment
curve (DMC) of CO molecule have been revisited within the framework of the
relativistic coupled-cluster approach, which incorporates non-perturbative
single, double, and triple cluster amplitudes (CCSDT) in conjunction with a
finite-field methodology. The generalized relativistic pseudo-potential model
was used for the effective introducing the relativity in all-electron
correlation treatment and accounting the quantum-electrodynamics (QED)
corrections within the model-QED-operator approach. The diagonal
Born-Oppenheimer correction to PEC has been evaluated using the CCSD approach.
The sensitivity of resulting PEC and DMC to variations in basis set parameters
and regular intramolecular perturbations were considered as well. The present
ab initio results are in a reasonable agreement with their most accurate
semi-empirical counterparts.
