Cluster-in-Molecule Method Combined with the Domain-Based Local Pair Natural Orbital Approach for Electron...

Area of Science:

• Computational chemistry
• Quantum chemistry
• Materials science

Background:

• The cluster-in-molecule (CIM) method was previously extended to periodic boundary conditions (PBCs) for electronic structure calculations.
• High computational costs of coupled cluster singles and doubles (CCSD) limit the application of PBC-CIM to small or medium unit cells.

Purpose of the Study:

• To reduce computational costs of the PBC-CIM method for periodic systems.
• To enable accurate electronic structure calculations at the coupled cluster singles and doubles with perturbative triples (CCSD(T)) level for periodic systems.
• To improve the accuracy of PBC-CIM through distant-pair correction.

Main Methods:

• Extension of the cluster-in-molecule (CIM) method to periodic boundary conditions (PBC-CIM).
• Integration of domain-based local pair natural orbital (DLPNO) methods for electron correlation calculations within PBC-CIM.
• Implementation of distant-pair correction for enhanced accuracy.
• Application of the combined PBC-CIM-DLPNO-CCSD(T) approach.

Main Results:

• The developed PBC-CIM-DLPNO-CCSD(T) method significantly reduces computational costs for periodic systems.
• Distant-pair correction improves accuracy with minimal additional cost.
• Accurate and efficient descriptions were achieved for the lattice parameter of cubic LiCl and adsorption on NaCl(100) and h-BN surfaces.
• Large basis sets are crucial for reliable cohesive energy calculations of molecular crystals, as shown for acetic acid.

Conclusions:

• The PBC-CIM-DLPNO-CCSD(T) method provides an accurate and efficient approach for electronic structure calculations of periodic systems.
• Distant-pair correction is a valuable addition for improving the accuracy of PBC-CIM.
• Careful selection of basis sets is essential for accurate cohesive energy calculations in molecular crystals.