Relativistic quintuple-zeta basis sets for the p block.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Relativistic Quantum Chemistry

Background:

• Accurate calculations for heavy elements require sophisticated basis sets that account for relativistic effects.
• Existing basis sets (double-zeta to quadruple-zeta) show limitations in achieving the basis set limit for these systems.

Purpose of the Study:

• To develop and present new, high-quality relativistic quintuple-zeta basis sets for p-block elements.
• To assess the performance of these basis sets in predicting atomic and molecular properties.

Main Methods:

• Optimization of occupied spinors at the Dirac-Coulomb self-consistent field level.
• Multireference internally contracted multireference configuration interaction (MRSDCI) calculations for valence and core correlating functions.
• Inclusion of diffuse functions optimized for anions or neighboring elements.

Main Results:

• Demonstrated smooth convergence towards the basis set limit with the new quintuple-zeta sets.
• Observed improved accuracy in calculated molecular bond lengths, dissociation energies, atomic ionization potentials, and electron affinities.
• Validated the basis sets by comparing results with previously available lower-zeta sets.

Conclusions:

• The developed relativistic quintuple-zeta basis sets significantly enhance the accuracy of calculations for heavy elements and their compounds.
• These basis sets, when combined with advanced relativistic and correlation treatments, are crucial for high-precision computational studies.
• The basis sets are publicly available for use in the scientific community.