Direct orbital selection within the domain-based local pair natural orbital coupled-cluster method

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Domain-based Local Pair Natural Orbital Coupled Cluster (DLPNO-CC) is widely used for calculating relative energies in chemical reactions.
• Existing multi-level DLPNO-CC approaches can be computationally expensive.
• Efficient methods are needed to focus computational resources on critical parts of molecular systems.

Purpose of the Study:

• To develop an automated multi-level DLPNO-CC method using direct orbital selection (DOS).
• To reduce computational cost while maintaining accuracy for reaction energy calculations.
• To provide a robust and user-independent computational tool for theoretical chemistry.

Main Methods:

• Integration of the multi-level DLPNO-CC-in-DLPNO-CC ansatz with the direct orbital selection (DOS) approach.
• Development of a conservative and transferable parameter set for the DOS procedure.
• Application to a diverse set of 61 chemical reactions with up to 174 atoms.

Main Results:

• The automated multi-level DLPNO-CC method requires no user input and is highly robust and accurate.
• Computational costs were reduced by a factor of 3 compared to standard methods.
• Parameters for DOS were found to be transferable across different reactions.
• Accurate predictions of relative energies for a wide range of reactions were achieved.

Conclusions:

• The developed automated multi-level DLPNO-CC method offers a significant improvement in computational efficiency.
• This approach provides a reliable and accurate tool for studying reaction energies and catalyst stability.
• The method's robustness and ease of use make it broadly applicable in computational chemistry research.