Tensor Hypercontraction Second-Order Møller-Plesset Perturbation Theory: Grid Optimization and Reaction Energies

Area of Science:

• Computational chemistry
• Quantum chemistry
• Electronic structure theory

Background:

• The tensor hypercontraction (THC) method has been introduced for electronic structure calculations.
• MP2 (Møller–Plesset perturbation theory) is a common method for approximating electron correlation.

Purpose of the Study:

• To present an improved algorithm for THC-MP2 calculations.
• To reduce memory requirements and prefactor costs of THC-MP2.
• To optimize quadrature grids for grid-based least-squares (LS) THC-MP2.

Main Methods:

• Developed a new algorithm for THC-MP2.
• Implemented a procedure to optimize quadrature grids for LS-THC-MP2.
• Generated optimized grids for first-row atoms using <100 points/atom.
• Benchmarked LS-THC-MP2 with optimized grids on conformational energies and reaction barriers.

Main Results:

• The new THC-MP2 algorithm lowers memory and prefactor requirements.
• Optimized quadrature grids incur negligible errors in computed energies.
• LS-THC-MP2 demonstrates negligible errors in absolute and relative energies.
• The method is applicable to larger basis sets like cc-pVDZ and cc-pVTZ.

Conclusions:

• The optimized LS-THC-MP2 method offers a computationally efficient approach for electronic structure calculations.
• The THC methodology is accurate and scalable for various chemical systems and basis sets.