Empirical correlation methods for temporary anions.

Area of Science:

• Theoretical Chemistry
• Computational Chemistry
• Quantum Chemistry

Background:

• Temporary anions are short-lived radical anions decaying via electron autodetachment.
• Accurate prediction of their energies is crucial but computationally expensive with ab initio methods.
• Existing empirical correlation methods have limitations in scope and applicability.

Purpose of the Study:

• To improve the accuracy and applicability of empirical correlation methods for predicting temporary anion energies.
• To investigate the role of electron correlation effects in empirical parameterization.
• To test the hypothesis that more accurate electronic structure calculations enhance predictive power.

Main Methods:

• Utilized the Hazi-Taylor stabilization method for theoretical justification.
• Compared empirical correlation schemes based on Hartree-Fock, Kohn-Sham, and equation-of-motion coupled-cluster (EOM-CC) methods.
• Employed a heterogeneous reference set of temporary anion states.

Main Results:

• Using more reliable energies for the confined electron significantly enhanced the predictive power of empirical schemes.
• Established useful correlations beyond closely related molecular families.
• Identified certain σ* states as remaining problematic, with reasons analyzed.

Conclusions:

• Improved electronic structure methods enhance empirical correlation schemes for temporary anions.
• The refined approach broadens the scope of applicability for these predictive methods.
• Preliminary results indicate potential for predicting bound anion energies cost-effectively.