Accelerating MP2C dispersion corrections for dimers and molecular crystals

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Materials Science

Background:

• Second-order Møller-Plesset perturbation theory (MP2) is crucial for modeling non-covalent interactions.
• The MP2C dispersion correction enhances MP2 accuracy but incurs significant computational expense.
• Existing methods often use dimer-centered basis functions, contributing to high computational costs.

Purpose of the Study:

• To develop a computationally efficient MP2C dispersion correction method.
• To adapt the MP2C correction for fragment-based molecular crystal studies.
• To significantly reduce the computational burden of dispersion corrections in periodic systems.

Main Methods:

• Implemented the MP2C dispersion correction using a monomer-centered basis set.
• Applied the new method to single dimer MP2 calculations.
• Integrated the monomer-centered MP2C algorithm with periodic symmetry for crystal calculations.

Main Results:

• The monomer-centered MP2C approach accelerated calculations several-fold for single dimers with minimal error increase.
• For molecular crystals, the combined monomer-centered basis and periodic symmetry reduced MP2C cost by two orders of magnitude.
• The computational expense of MP2C became negligible for crystals like aspirin and oxalyl dihydrazide.

Conclusions:

• The monomer-centered basis MP2C method offers a substantial speed-up for dispersion corrections.
• This approach makes accurate MP2C calculations computationally feasible for large systems and molecular crystals.
• The enhanced efficiency maintains the high accuracy of MP2C for non-covalent interactions.