On the accuracy of ab initio methods in predicting the electric dipole moment function of carbon monoxide

Accurate electric dipole moment function of the CO molecule in its ground electronic state X 1 Σ + has been determined using the single-reference coupled-cluster approach, up to the CCSDTQP level of approximation, in conjunction with the augmented core-valence correlation-consistent basis sets, aug-cc-pCV n Z, up to octuple-zeta quality. The ab initio predicted function is compared with its experimentally-derived counterparts. The accuracy of applied theoretical methods is discussed. • The electric dipole moment function of CO was predicted at the high level of theory. • Some vibration–rotation transition dipole moments were predicted and compared with experimental data. • The accuracy of applied theoretical methods is discussed.