Describing Strong Correlation with Block-Correlated Coupled Cluster Theory

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Strongly correlated systems pose significant challenges for traditional electronic structure methods.
• Accurate modeling of multiple bond breaking is crucial for understanding chemical reactions and material properties.

Purpose of the Study:

• To propose and implement a novel multireference electronic structure method, GVB-BCCC, for strongly correlated systems.
• To evaluate the performance of GVB-BCCC for multiple bond breaking scenarios.

Main Methods:

• Development and ab initio implementation of the block-correlated coupled cluster (BCCC) method using a generalized valence bond (GVB) wave function.
• Application of the GVB-BCCC2b method to tridecane for simulating simultaneous C-C bond dissociation.

Main Results:

• GVB-BCCC provides satisfactory descriptions of multiple bond breaking, even with a qualitatively incorrect GVB reference function.
• GVB-BCCC2b results for tridecane's potential energy surfaces closely match those from the density matrix renormalization group (DMRG) method.

Conclusions:

• The GVB-BCCC method is an attractive and accurate approach for studying strongly correlated systems.
• This method shows significant potential for accurately describing complex chemical processes like simultaneous bond dissociation.