Modified Interaction-Strength Interpolation Method as an Important Step toward Self-Consistent Calculations.

Area of Science:

• * Quantum Chemistry
• * Computational Materials Science
• * Electronic Structure Theory

Background:

• * Original point charge plus continuum (PC) model exhibits divergences for large density gradients.
• * Modified PC (mPC) model addresses these failures, enabling more robust calculations.
• * Modified interaction-strength interpolation (mISI) builds upon mPC's strengths.

Purpose of the Study:

• * To assess the performance of the mISI method for molecular systems.
• * To evaluate mISI's accuracy for thermochemistry, correlation energies, and noncovalent interactions.
• * To investigate mISI's behavior with harmonium atoms and functional derivatives.

Main Methods:

• * Application of the mISI method to various molecular systems and model systems.
• * Calculation of thermochemistry properties, correlation energies, and vertical ionization potentials.
• * Testing mISI with and without semilocal approximations of second-order Görling-Levy (GL2) perturbation theory.

Main Results:

• * mISI demonstrates systematic improvement over the original ISI method across all tested properties.
• * Calculations involving GL2 approximations within mISI show a significant worsening of results.
• * The mISI method proves effective for diverse molecular and atomic systems.

Conclusions:

• * mISI represents a significant advancement over the ISI method, offering enhanced accuracy.
• * The inclusion of GL2 approximations negatively impacts mISI's performance.
• * Further development of mISI holds promise for more accurate electronic structure calculations.