Interaction-Region Decoupling through Structured Absorbing Potentials: A Framework for Scalable Time-Dependent Quantum Dynamics Calculations

TL;DR

This paper presents a new IRD method using structured absorbing potentials to efficiently simulate complex molecular reactions with high accuracy, significantly reducing computational costs and enabling routine quantum calculations for challenging reactions.

Contribution

The paper introduces a novel IRD framework that integrates structured absorbing potentials with standard TDWP methods, improving efficiency and accuracy in quantum reaction simulations.

Findings

Achieves state-resolved accuracy for complex reactions.

Reduces computational cost by over two orders of magnitude.

Enables routine quantum treatment of previously intractable reactions.

Abstract

Accurate quantum mechanical treatment of molecular reactions remains a longstanding challenge, especially for reactions involving deep potential wells and long-lived intermediate complexes. Here, we introduce an interaction region decoupling (IRD) strategy that incorporates structured absorbing potentials to dynamically partition the interaction region into reactant and product subspaces. The IRD framework integrates naturally with standard TDWP propagation schemes and enables the construction of region-specific basis sets, dramatically enhancing computational efficiency. Benchmark applications to the F + HD and O + OH reactions demonstrate that this approach achieves state-resolved accuracy while reducing computational cost by over two orders of magnitude. This strategy paves the way for routine quantum mechanical treatment of complex-forming four-atom reactions previously considered intractable.