Error-consistent basis sets for large-core ECPs for elements La-Lu.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Atomic and Molecular Physics

Background:

• Effective core potentials (ECPs) simplify calculations by replacing core electrons with a potential.
• Lanthanides present unique computational challenges due to their complex electronic structures.
• Existing basis sets may not fully capture the accuracy needed for lanthanide ECPs.

Purpose of the Study:

• To extend the Karlsruhe def2-basis sets for lanthanide large-core ECPs (lcECPs).
• To optimize new basis sets (SV, TZV, QZV) for various f-electron occupations.
• To ensure error-consistency with existing def2-basis sets.

Main Methods:

• Optimization of segmented contracted Gaussian basis sets using atomic Hartree-Fock calculations.
• Development of basis sets (lcecp-k-XV) for lanthanides (La-Lu) with lcECPs.
• Assessment of error-consistency by comparing with basis set limits and all-electron calculations for 120 molecules.

Main Results:

• Successfully optimized and extended def2-basis sets for lanthanide lcECPs.
• Developed lcecp-k-XV basis sets for different f-electron configurations (f^n-k).
• Demonstrated conformity with the def2-series regarding error-consistency.

Conclusions:

• The new basis sets provide accurate and error-consistent descriptions for lanthanide calculations.
• This extension significantly improves computational chemistry tools for studying lanthanide compounds.
• The optimized sets facilitate more reliable predictions of molecular properties.