Revised model core potentials of s-block elements.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Electronic structure theory

Background:

• Accurate electronic structure calculations are crucial for understanding chemical properties.
• Developing efficient computational methods for heavy elements is challenging.
• Model core potentials (MCPs) offer a way to reduce computational cost by treating core electrons implicitly.

Purpose of the Study:

• To develop new, accurate model core potentials (MCPs) for s-block elements (Na to Ra).
• To explicitly include outer core (n-1)s and (n-1)p electrons in the MCP treatment.
• To validate the performance of the new MCPs for atomic and molecular electronic structure calculations.

Main Methods:

• Development of novel model core potentials (MCPs) for s-block elements.
• Inclusion of outer core (n-1)s and (n-1)p electrons alongside valence ns electrons.
• Incorporation of specific correlating functions to enhance accuracy.
• Comparison of results with established all-electron correlation consistent basis sets (e.g., Dunning's basis sets).

Main Results:

• The new MCP basis sets demonstrate excellent performance in describing electronic structures.
• Accurate ionization potentials for atoms were obtained.
• Very good spectroscopic constants for ionic and covalent molecules were achieved.
• Results closely align with those from computationally expensive all-electron calculations.

Conclusions:

• The developed MCPs provide a computationally efficient and accurate method for studying s-block elements.
• Explicit treatment of outer core electrons in MCPs significantly improves accuracy.
• These new MCPs are a valuable tool for electronic structure calculations of atoms and molecules containing s-block elements.