Abstract We employ a fully close-coupled three-dimensional time-dependent wavepacket (FCC-3D-TDWP) approach in hyperspherical coordinates to investigate the H + H<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$_2$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> exchange reaction on recently constructed ground adiabatic as well as Beyond Born–Oppenheimer (BBO)-based three-state diabatic potential energy surfaces (J. Phys. Chem. A 2025 129 6315–6332). For the reaction, H + H<InlineEquation ID="IEq4"> <EquationSource Format="TEX">$_2$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>(<InlineEquation ID="IEq5"> <EquationSource Format="TEX">$v=0$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>v</mi> <mo>=</mo> <mn>0</mn> </mrow> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$j=0$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>j</mi> <mo>=</mo> <mn>0</mn> </mrow> </math></EquationSource> </InlineEquation>) <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$\rightarrow$</EquationSource> <EquationSource Format="MATHML"><math> <mo stretchy="false">→</mo> </math></EquationSource> </InlineEquation> H<InlineEquation ID="IEq8"> <EquationSource Format="TEX">$_2$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>(<InlineEquation ID="IEq9"> <EquationSource Format="TEX">$v'$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>v</mi> <mo>′</mo> </msup> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq10"> <EquationSource Format="TEX">$j'$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>j</mi> <mo>′</mo> </msup> </math></EquationSource> </InlineEquation>) + H over the total energy range <InlineEquation ID="IEq11"> <EquationSource Format="TEX">$0.6 \le E_\textrm{tot} \le 4.5$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>0.6</mn> <mo>≤</mo> <msub> <mi>E</mi> <mtext>tot</mtext> </msub> <mo>≤</mo> <mn>4.5</mn> </mrow> </math></EquationSource> </InlineEquation> eV, adiabatic state-to-state reaction probabilities, cross-sections, and product rotational distributions are calculated for total angular momenta up to <InlineEquation ID="IEq12"> <EquationSource Format="TEX">$J=50$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>J</mi> <mo>=</mo> <mn>50</mn> </mrow> </math></EquationSource> </InlineEquation>, whereas for the diabatic case, state-to-state and total reaction probabilities are computed at <InlineEquation ID="IEq13"> <EquationSource Format="TEX">$J=0$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>J</mi> <mo>=</mo> <mn>0</mn> </mrow> </math></EquationSource> </InlineEquation>. Calculated adiabatic and diabatic reaction attributes are compared with earlier theoretical results. Though the reaction probabilities as well as cross-sections calculated on adiabatic potential energy surface are qualitatively close to the earlier theoretical profiles, the reaction probability at <InlineEquation ID="IEq14"> <EquationSource Format="TEX">$J=0$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>J</mi> <mo>=</mo> <mn>0</mn> </mrow> </math></EquationSource> </InlineEquation> on diabatic surfaces is substantially different from existing theoretical ones. The difference originates from the inclusion of ab initio computed non-adiabatic coupling terms in the construction of diabatic Hamiltonian and thereafter, in dynamical calculations. Graphical abstract

The effect of nonadiabaticity in H + H$_2$ reaction: A quantum wavepacket dynamics on adiabatic and diabatic potential energy surfaces

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2026年7月25日

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Ahitagni Roy,
Amarendra Ghosh,
Saikat Hazra,
Satrajit Adhikari

摘要

Abstract

We employ a fully close-coupled three-dimensional time-dependent wavepacket (FCC-3D-TDWP) approach in hyperspherical coordinates to investigate the H + H $_2$ $_{2}$ exchange reaction on recently constructed ground adiabatic as well as Beyond Born–Oppenheimer (BBO)-based three-state diabatic potential energy surfaces (J. Phys. Chem. A 2025 129 6315–6332). For the reaction, H + H $_2$ $_{2}$ ( $v=0$ $v = 0$ , $j=0$ $j = 0$ ) $\rightarrow$ $\to$ H $_2$ $_{2}$ ( $v'$ $v^{'}$ , $j'$ $j^{'}$ ) + H over the total energy range $0.6 \le E_\textrm{tot} \le 4.5$ $0.6 \leq E_{tot} \leq 4.5$ eV, adiabatic state-to-state reaction probabilities, cross-sections, and product rotational distributions are calculated for total angular momenta up to $J=50$ $J = 50$ , whereas for the diabatic case, state-to-state and total reaction probabilities are computed at $J=0$ $J = 0$ . Calculated adiabatic and diabatic reaction attributes are compared with earlier theoretical results. Though the reaction probabilities as well as cross-sections calculated on adiabatic potential energy surface are qualitatively close to the earlier theoretical profiles, the reaction probability at $J=0$ $J = 0$ on diabatic surfaces is substantially different from existing theoretical ones. The difference originates from the inclusion of ab initio computed non-adiabatic coupling terms in the construction of diabatic Hamiltonian and thereafter, in dynamical calculations.

Graphical abstract

The effect of nonadiabaticity in H + H\(_2\) reaction: A quantum wavepacket dynamics on adiabatic and diabatic potential energy surfaces

摘要