Gaussian basis sets for CO₂ molecule generated with the molecular improved generator coordinate Hartree–Fock method

Abstract

The molecular improved generator coordinate Hartree–Fock (MIGCHF) method is used to generate increasing size atom-centered Gaussian basis sets for the CO₂ molecule. From these basis sets total HF energies and second-order correlation energies were calculated and compared with results obtained with other approaches. Considering our largest basis set, the HF energy is in error by 98 μhartree and the second-order correlation energy corresponds to ∼95.6% of an estimate of the limiting value. The relevance of the present calculations is to show the accuracy that can be achieved in studies of small polyatomic molecules with the MIGCHF method.