Computation of potential energy surfaces with the multireference correlation consistent composite approach.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• Accurately describing the electronic structure of molecules, especially during bond dissociation, is computationally challenging.
• Existing composite methods often struggle with systems exhibiting significant multireference character.

Purpose of the Study:

• Introduce a novel multireference composite method based on the correlation consistent Composite Approach (ccCA).
• Validate the new multireference ccCA method by computing potential energy surfaces (PESs) for N2 and C2.

Main Methods:

• Development of the multireference ccCA (MRccCA) computational chemistry approach.
• Calculation of potential energy surfaces (PESs) for diatomic molecules N2 and C2.

Main Results:

• The MRccCA method successfully computed the PESs for N2 and C2.
• The computed PESs demonstrate the method's ability to handle significant multireference character during dissociation.

Conclusions:

• The developed MRccCA method provides a robust tool for calculating PESs of systems with strong multireference character.
• The study confirms the suitability of MRccCA for rigorous testing of multireference computational chemistry methods.