Regularized and Opposite Spin-Scaled Functionals from Møller-Plesset Adiabatic Connection─Higher Accuracy at Lower...

Area of Science:

• Quantum Chemistry
• Computational Chemistry

Background:

• Noncovalent interactions (NCIs) are fundamental to various scientific disciplines.
• Accurate simulation of NCIs is crucial for advancing molecular modeling.

Purpose of the Study:

• To develop an improved computational methodology for simulating noncovalent interactions.
• To enhance the accuracy of quantum-chemical calculations for NCIs.

Main Methods:

• A novel approach combining Møller-Plesset adiabatic connection (MP AC) interpolation with MP2 regularization and spin-scaling.
• The resulting method is termed c_osκ_os-SPL2.
• Computational scaling is N⁴.

Main Results:

• The c_osκ_os-SPL2 method demonstrates superior accuracy for NCIs compared to individual component strategies.
• It is computationally competitive with, and often outperforms, more expensive double hybrid methods for NCIs.
• Exceptional accuracy was observed for anionic halogen-bonded complexes, exceeding standard dispersion-corrected DFT by 3-5 times.

Conclusions:

• The c_osκ_os-SPL2 method provides a highly accurate and efficient approach for simulating noncovalent interactions.
• This method offers significant advantages for studying systems like anionic halogen-bonded complexes.