The EOM-CC studies of low-lying electronic states of , CCl2 and

The equation-of-motion single-reference coupled-cluster (EOM-CC) method was combined with the aug-cc-pVTZ basis set to obtain the geometries and excitation energies of an extensive set of low-lying excited states of NO 2 - , CCl2 and OF 2 + , which was previously studied by the multireference MRSDCI/DZ+P approach. The EOM-CC/aug-cc-pVTZ strategy yielded results close to the MRSDCI/DZ+P data and the experiment, which warrants its application for estimating unavailable experimental values.