A new generation of effective core potentials: Selected lanthanides and heavy elements II

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Chemistry

Background:

• Accurate theoretical modeling of heavy elements is crucial for materials science and chemistry.
• Existing effective core potentials (ECPs) may lack accuracy for systems with significant relativistic and correlation effects.

Purpose of the Study:

• To develop a new set of correlation-consistent effective core potentials (ccECPs) for heavy s, p, d, and f-block elements.
• To ensure these ccECPs are accurate, transferable, and suitable for valence-only calculations.

Main Methods:

• Designed ccECPs using minimal Gaussian parameterization and a relativistic coupled-cluster framework.
• Incorporated averaged relativistic effective potentials (AREPs) and effective spin-orbit terms.
• Optimized potentials based on all-electron (AE) atomic spectra, norm-conservation, and spin-orbit splittings.

Main Results:

• Developed ccECPs for Rb, Sr, Cs, Ba, In, Sb, Pb, Ru, Cd, La, Ce, and Eu.
• Validated transferability using molecular oxides and hydrides, showing excellent agreement with AE calculations.
• Achieved chemical accuracy in bond dissociation energies and equilibrium bond lengths.

Conclusions:

• The new ccECPs offer an accurate and transferable framework for valence-only electronic structure calculations.
• These potentials are suitable for systems with significant relativistic and correlation effects.
• Facilitates advanced computational studies in materials science and chemistry involving heavy elements.