Atomic isotropic hyperfine properties for second row elements (Al-Cl)

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Atomic Physics

Background:

• Isotropic hyperfine properties are crucial for understanding atomic structure and interactions.
• Accurate calculations are needed for elements across the periodic table.

Purpose of the Study:

• To systematically compute isotropic hyperfine properties for second-row elements (Al-Cl).
• To investigate the contributions of different electron shells to spin density.
• To establish the relationship between spin density and atomic number.

Main Methods:

• Employed a composite computational approach with extensive basis sets (up to aug-cc-pCV7Z).
• Utilized configuration interaction and coupled cluster methods for high accuracy.
• Calculated nonrelativistic ground state values for Al, Si, P, S, and Cl.

Main Results:

• Obtained precise isotropic hyperfine values for Al, Si, P, S, and Cl.
• Identified a substantial K shell contribution to nuclear spin density.
• Observed that L and M shell contributions largely cancel the K shell effect.
• Found an approximately linear correlation between spin density and atomic number.

Conclusions:

• The study provides benchmark isotropic hyperfine properties for key second-row elements.
• Electron shell contributions to spin density are significant and complex.
• The linear relationship offers a simplified model for predicting spin density trends.