Jahn–Teller intersections involving excited states of the F+H2 system: Identification and influence on the reaction system

Das, Anita; Mukhopadhyay, Debasis

doi:10.1016/j.chemphys.2012.12.007

Cited by 11 publications

(3 citation statements)

References 49 publications

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“…On the other hand, Li et al constructed a new PES employing double many-body expansion (DMBE) on the basis of MRCI+Q ab initio calculation. Later, in a series of studies, the role of Jahn–Teller and Renner–Teller conical intersections for this title system was investigated by Das et al − Most recently, Adhikari and co-workers calculated the lowest three adiabatic PESs of F + H 2 (1 2 A′, 2 2 A′, and 1 2 A″) and the nonadiabatic coupling terms (NACTs) between those states, where first-principles based beyond Born–Oppenheimer (BBO) theory , was employed for an accurate description of nuclear coupling while generating multistate diabatic PESs the effect of SO coupling. At this point, it is noteworthy that a generalized algorithm, “ADT” has recently been developed by Adhikari and co-workers to construct theoretically “exact” and numerically “accurate” diabatic PESs for any number of coupled nuclear degrees of freedom (DOF) and electronic states.…”

Section: Introductionmentioning

confidence: 99%

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

2022

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We employ coupled three-dimensional (3D) time dependent wave packet formalism in hyperspherical coordinates for reactive scattering problem on the newly constructed ab initio calculated ground adiabatic potential energy surface for the F + H2/D2 reaction. The convergence profiles for various reactive channels are depicted at low collision energy regimes with respect to the total angular momentum (J) quantum numbers. For two different reactant diatomic molecules (H2 and D2) initially at their respective ground roto-vibrational state (v = 0, j = 0), calculated state-to-state as well as total integral cross sections as a function of collision energy, temperature dependent rate constants, and the kinetic isotope effect for various reactivity profiles of F + H2 and F + D2 reactions are presented along with previous theoretical and experimental results.

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Section: Introductionmentioning

confidence: 99%

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

2022

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“…In the present article we consider a well established approach, introduced some time ago, , that yields rigorous diabatic potential energy surfaces (PES) with high accuracy for large regions in configuration space. It is based on numerous interacting Born–Oppenheimer (adiabatic) PESs and therefore requires deriving a set of mixing angles, γ ij ( s ), to form the required adiabatic-to-diabatic transformations (ADT). − It is well-known that these angles are formed by the Born–Oppenheimer nonadiabatic coupling terms (NACT) that have their origin either in the Jahn–Teller (JT) conical intersections (ci) − or in the Renner–Teller (RT) degeneracy. − ...…”

Section: Introductionmentioning

confidence: 99%

Study of Topological Effects Concerning the Lowest A″ and the Three A′ States for the CO₂⁺ Ion

2015

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A study of the topological effects, viz., the Jahn-Teller (JT) and Renner-Teller (RT) effects, in CO2(+) has been carried out by calculating nonadiabatic coupling terms (NACTs) at the state-averaged CASSCF level using the cc-pVTZ basis set for the lowest three A' states and one A″ state along a circular contour. Using the NACTs, the privileged adiabatic-to-diabatic transformation (ADT) angles (γ12) for 1A' and 2A' states of CO2(+) have been calculated along various circular contours. Employing one of the oxygen atoms as the test particle exposed two conical intersections (ci) located on each side of the CO diatom. The main purpose of this study is to explore the possibility of forming reliable diabatic potential energy surfaces for this system. Success in achieving this goal is guaranteed by the ability to calculate quantized privileged ADT angles along closed contours covering large regions in configuration space (see, e.g., J. Phys. Chem. A 2014 , 118 , 6361 ). The calculations were carried out for two and three JT states. In most cases very nice quantization has been achieved although the calculations were frequently done, as required, for large regions in configuration space (sometimes ≥18 Å(2)). In one case, for which the quantization was not gratifying, the inclusion of the RT effect modified it considerably.

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“…It is well-known that the existing BO lower adiabatic PES produces results that fit reasonably well the known relevant experimental results ranging from the temperature dependent rate constants up to the energy dependent, most sensitive, differential cross sections. It is also well-known that this system possesses Jahn–Teller (JT) conical intersections ( ci ), − formed by the four lower states 1A′, 2A′, 3A′, and 4A′, which are located at three different points along the minimum energy path of the reagents channel. Hence, if a system is supposed to be affected by JT- ci s, this system looks promising in this sense at least.…”

Section: Introductionmentioning

confidence: 99%

Dressed Adiabatic and Diabatic Potentials To Study Topological Effects for F + H₂

et al. 2014

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We report here on the two lowest, rigorous-accurate diabatic potential energy surfaces (PES), for the F + H2 system, as calculated by including the two dominant topological effects of this system at the low energy region, namely, the Jahn-Teller effect and the Renner-Teller effect. Both effects were treated in the most rigorous way as demanded by the Born-Oppenheimer approach. No approximations were made, and in those cases where convergence was required, it was satisfied. In other words, convergence was attained in all situations. The numerical part that includes the calculation of the two lowest ab initio adiabatic PESs and the corresponding nonadiabatic coupling terms (NACTs) was carried out using the MOLPRO program. The required diabatic potentials are calculated by employing these ab initio adiabatic PESs and the corresponding adiabatic-to-diabatic angles as obtained employing the above-mentioned ab initio NACTs. The relevance of these Renner-Teller/Jahn-Teller diabatic potentials is studied by comparing the dressed-lowest ab initio adiabatic PES and the one formed by diagonalizing the dressed-diabatic 2 × 2 potential matrix. The dressed-potentials are calculated employing the vib-rotational manifold derived for each of the three surfaces, namely, the lowest adiabatic potential and the two diabatic ones. This kind of study was recently recommended by Lipoff and Herschbach ( Mol. Phys. 2010 , 108 , 1133 ) as a "blessed-practice" for the relevance of any PES. In the present case significant differences were revealed between the two types of dressed-adiabatic PESs, eventually, indicating that the lowest, ab initio PES (due to the Born-Oppenheimer approximation) is not adequate for low energy processes.

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Jahn–Teller intersections involving excited states of the F+H2 system: Identification and influence on the reaction system

Cited by 11 publications

References 49 publications

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Study of Topological Effects Concerning the Lowest A″ and the Three A′ States for the CO₂⁺ Ion

Dressed Adiabatic and Diabatic Potentials To Study Topological Effects for F + H₂

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Jahn–Teller intersections involving excited states of the F+H2 system: Identification and influence on the reaction system

Cited by 11 publications

References 49 publications

Accurate Calculation of Rate Constant and Isotope Effect for the F + H2 Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Accurate Calculation of Rate Constant and Isotope Effect for the F + H2 Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Study of Topological Effects Concerning the Lowest A″ and the Three A′ States for the CO2+ Ion

Dressed Adiabatic and Diabatic Potentials To Study Topological Effects for F + H2

Contact Info

Product

Resources

About

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Accurate Calculation of Rate Constant and Isotope Effect for the F + H₂ Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface

Study of Topological Effects Concerning the Lowest A″ and the Three A′ States for the CO₂⁺ Ion

Dressed Adiabatic and Diabatic Potentials To Study Topological Effects for F + H₂