How does basis set superposition error change the potential surfaces for hydrogen-bonded dimers?

摘要: We describe a simple method to automate the geometric optimization of molecular orbital calculations supermolecules on potential surfaces that are corrected for basis set superposition error using counterpoise (CP) method. This is applied H‐bonding complexes HF/HCN, HF/H2O, and HCCH/H2O 6‐31G(d,p) D95++(d,p) sets at both Hartree–Fock second‐order Mo/ller–Plesset levels. report interaction energies, geometries, vibrational frequencies these CP‐optimized surfaces; compare them with similar values calculated traditional methods, including (more traditional) single point CP correction. Upon CP‐corrected surface, energies become more negative (before corrections) stretching vibrations decrease in all cases. The extent effects vary from extremely small quite large depending complex calculational relative magnitudes corrections cannot be predicted H‐bond alone.