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Toward ab initio realizations of Collins's conjecture
Abdulrahman Y Zamani1, Kevin Carter-Fenk1
1Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
The Journal of Chemical Physics
|July 15, 2025
Summary
This study presents an entropy-inspired ab initio method to improve electronic structure calculations. The approach accurately captures electron correlation, enhancing predictions for bond dissociation energies in molecules.
Area of Science:
- Quantum Chemistry
- Computational Physics
Background:
- Accurate calculation of electron correlation is crucial for predicting molecular properties.
- Traditional perturbation theories often neglect static correlation, limiting their accuracy for certain systems.
Purpose of the Study:
- To develop an ab initio method incorporating entropy for improved electron correlation.
- To enhance the accuracy of calculating single bond dissociation energies (BDEs).
Main Methods:
- Formulation of an entropy-inspired repartitioning of the electronic Hamiltonian.
- Introduction of a parameter to control one-electron density accuracy at the MP2 level.
- Application of Collins's conjecture relating electron correlation to Jaynes entropy.
Main Results:
- Achieved one-electron densities comparable to full configuration interaction for single-bond dissociation.
- The method approaches the accuracy of generalized valence bond theory for BDEs.
- Developed generic BDE parameters accurate to within 7% for strongly correlated systems.
Conclusions:
- The proposed method effectively captures both dynamical and nondynamical correlation effects.
- This work offers a way to reincorporate static correlation in perturbation theories.
- The findings have implications for computational chemistry and materials science.
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