Predicting the Post-Hartree-Fock Electron Correlation Energy of Complex Systems with the Information-Theoretic...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate prediction of electron correlation energies is crucial for understanding molecular behavior.
• Existing methods for calculating post-Hartree-Fock energies are computationally expensive.
• Developing cost-effective methods to predict electron correlation energies remains an open challenge.

Purpose of the Study:

• To expand the linear regression (LR) combined with information-theoretic approach (ITA) protocol for predicting electron correlation energies.
• To test the LR(ITA) method on a wider range of complex systems, including isomers, polymers, and molecular clusters.
• To validate the accuracy of LR(ITA) against established methods like linear-scaling generalized energy-based fragmentation (GEBF).

Main Methods:

• Application of the LR(ITA) protocol to diverse chemical systems.
• Utilized Hartree-Fock calculations to obtain necessary quantities for LR(ITA).
• Employed the linear-scaling generalized energy-based fragmentation (GEBF) method for large molecular clusters.

Main Results:

• The LR(ITA) protocol successfully predicted post-Hartree-Fock electron correlation energies for octane isomers, polymers (polyne, polyene, polymethineimine, acene), and various molecular clusters (metallic, covalent, hydrogen-bonded, dispersion-bound).
• LR(ITA) achieved chemical accuracy comparable to more computationally intensive methods.
• For benzene clusters, LR(ITA) demonstrated accuracy on par with the GEBF method.

Conclusions:

• Information-theoretic approach (ITA) quantities, when used with linear regression (LR), provide a reliable and efficient method for predicting electron correlation energies.
• The LR(ITA) method is applicable to a broad spectrum of complex chemical systems.
• This approach offers a computationally inexpensive route to obtain accurate electron correlation energies, valuable for theoretical chemistry research.