An efficient algorithm for capturing quantum effects in classical reactive scattering: application to D + H+3 → H₂D⁺...

Area of Science:

• * Chemical Physics
• * Theoretical Chemistry
• * Computational Chemistry

Background:

• * Accurate calculation of reaction thresholds requires considering quantum effects like zero-point energy (ZPE).
• * Previous methods for including ZPE in classical reactive scattering have limitations.
• * The D + H+3 reaction is important in astrophysics and exhibits significant quantum effects.

Purpose of the Study:

• * To present an efficient algorithm for incorporating ZPE effects into classical reactive scattering.
• * To apply this new algorithm to the astrophysically relevant D + H+3 reaction.
• * To validate the algorithm by comparing its results with experimental and other theoretical methods.

Main Methods:

• * Extension of the quasi-classical trajectory (QCT) Gaussian binning method.
• * Inclusion of zero-point energy (ZPE) effects in classical reactive scattering.
• * Application to the D + H+3 reaction system.

Main Results:

• * The developed algorithm efficiently includes ZPE effects in classical reactive scattering.
• * Computed rate constants for the D + H+3 reaction closely match experimental data.
• * Results also align well with Ring Polymer Molecular Dynamics (RPMD) calculations.

Conclusions:

• * The new general algorithm provides an efficient way to include ZPE effects in classical reactive scattering.
• * The method is accurate for systems with significant quantum effects, like D + H+3.
• * This approach offers a reliable alternative for studying chemical reactions where other methods are problematic.