Ab initio electronic structure methods 1 Calculations 1 Complete basis set limit Configuration-interaction calculations 1 Electronic structure 1 Electronic structure theory 1 Excitation energy 1 Excited states 1 Incremental Strategy 1 Medium-sized molecules 1 Molecules 1 Numerical methods 1 Vertical excitation energy 1 Wave function method 1 Wave functions 1 benchmark 1 coupled cluster theory 1 database 1 excitation energies 1 excited states 1 full configuration interaction 1