The local electron affinity for non-minimal basis sets.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Calculating local electron affinity (EA(L)) is crucial for understanding molecular properties.
• Traditional semiempirical molecular orbital techniques often produce inaccurate EA(L) values when polarization functions are included.
• These inaccuracies stem from the over-contribution of polarization functions to the calculated EA(L).

Purpose of the Study:

• To introduce a novel technique, intensity filtering, for the accurate calculation of local electron affinity (EA(L)).
• To enable the use of semiempirical molecular orbital techniques with polarization functions for reliable EA(L) computations.
• To extend the applicability of accurate EA(L) calculations to ab initio and density functional theory methods.

Main Methods:

• Development and application of the intensity filtering technique.
• Selection of valence-like virtual orbitals using intensity filtering.
• Calculation of local electron affinity (EA(L)) with and without intensity filtering.

Main Results:

• Intensity filtering successfully selects appropriate virtual orbitals for EA(L) calculations.
• The technique resolves spurious EA(L) values previously dominated by polarization functions in semiempirical methods.
• Intensity filtering demonstrates potential applicability to ab initio and density functional theory calculations with large basis sets.

Conclusions:

• Intensity filtering is an effective method for obtaining accurate local electron affinity (EA(L)) values.
• This technique enhances the reliability of semiempirical molecular orbital calculations including polarization functions.
• Intensity filtering broadens the scope of accurate EA(L) computations across various quantum chemistry methodologies.