Tighter multipole-based integral estimates and parallel implementation of linear-scaling AO-MP2 theory

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Second-order Møller-Plesset perturbation theory (MP2) is crucial for accurate electronic structure calculations.
• Atomic-orbital (AO) based MP2 methods face challenges with computational cost, especially for large systems and basis sets.
• Efficient selection of significant two-electron integrals is a bottleneck in AO-MP2 calculations.

Purpose of the Study:

• To develop a novel, efficient screening procedure for AO-based MP2 calculations.
• To enable the use of larger basis sets and molecular systems in AO-MP2.
• To achieve linear scaling with controlled numerical accuracy.

Main Methods:

• Implementation of a multipole-based integral estimates (MBIE) screening method within AO-MP2.
• Exploitation of multipole coupling (1/R^4, 1/R^6) for integral product screening.
• Development of a parallel implementation of the linear-scaling AO-MP2 method.

Main Results:

• The MBIE screening significantly improves the efficiency of preselecting two-electron integrals.
• Linear scaling of computational cost is achieved with controlled accuracy.
• The method successfully scales to large molecular systems, including a ribozyme fragment (497 atoms) and a DNA system (1052 atoms).

Conclusions:

• The novel MBIE screening procedure offers a highly efficient approach for AO-MP2 calculations.
• The developed method allows for accurate and scalable electronic structure computations on large molecular systems.
• This advancement facilitates more extensive theoretical studies in computational and quantum chemistry.