Finding Chemical Reaction Paths with a Multilevel Preconditioning Protocol.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Chemical reaction dynamics

Background:

• Accurate quantum-chemical calculations for chemical reaction pathways are computationally expensive.
• Existing methods require significant computational resources, limiting their application.

Purpose of the Study:

• To demonstrate a multilevel preconditioning scheme for accelerating quantum-chemical string calculations.
• To reduce the computational cost of finding minimum-energy paths for chemical reactions.

Main Methods:

• Application of a multilevel preconditioning scheme to quantum-chemical string calculations.
• Utilizing a semiempirical method to precondition density functional theory (DFT).
• Finding minimum-energy paths for malonaldehyde tautomerization and chorismate to prephanate rearrangement.

Main Results:

• The multilevel preconditioning scheme significantly accelerates quantum-chemical string calculations.
• Preconditioning DFT with a semiempirical method reduced computational costs by several fold for converged reaction paths.
• The method shows promise for accelerating free energy calculations under controlled thermal noise.

Conclusions:

• Multilevel preconditioning is an effective strategy for accelerating the computation of chemical reaction pathways.
• This approach offers a substantial reduction in computational cost for DFT-based reaction path calculations.
• The method has potential applications in more complex calculations, including free energy studies.