Calculation of bound and resonance states of HO2 for nonzero total angular momentum

Abstract

Bound and resonance states of HO 2 have been calculated quantum mechanically by the Lanczos homogeneous filter diagonalization method ͓Zhang and Smith, Phys. Chem. Chem. Phys. 3, 2282 ͑2001͒; J. Chem. Phys. 115, 5751 ͑2001͔͒ for nonzero total angular momentum Jϭ1,2,3. For lower bound states, agreement between the results in this paper and previous work is quite satisfactory; while for high lying bound states and resonances these are the first reported results. A helicity quantum number ⍀ assignment ͑within the helicity conserving approximation͒ is performed and the results indicate that for lower bound states it is possible to assign the ⍀ quantum numbers unambiguously, but for resonances it is impossible to assign the ⍀ helicity quantum numbers due to strong mixing. In fact, for the high-lying bound states, the mixing has already appeared. These results indicate that the helicity conserving approximation is not good for the resonance state calculations and exact quantum calculations are needed to accurately describe the reaction dynamics for HO 2 system. Analysis of the resonance widths shows that most of the resonances are overlapping and the interferences between them lead to large fluctuations from one resonance to another. In accord with the conclusions from earlier Jϭ0 calculations, this indicates that the dissociation of HO 2 is essentially irregular.

Accurate combined-hyperbolic-inverse-power-representation of ab initio potential energy surface for the hydroperoxyl radical and dynamics study of $\bf O+OH$O+OH reaction

“…5 The potential energy surface (PES) of HO 2 (X 2 A ) has been much studied at various levels of ab initio theory. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] It is key both for calculations of bound vibrational states and resonances [22][23][24][25][26][27][28][29] as well as reactive scattering either via time-independent or time-dependent methods. 22,[30][31][32][33][34][35][36][37][38][39] Three PESs have been mostly utilized: Melius-Blint, 6 double manybody expansion (DMBE IV 16 ), and diatomics-in-molecules (DIM) 17 (as slightly updated; 40 a related form is available 41 but not yet used for dynamics).…”

Quantum Dynamics of Oxyhydrogen Complex-Forming Reactions for the HO2 and HO3 Systems

“…TIQM calculations on H+O 2 reaction are extended to total angular momentum J>0 and Coriolis coupling was explicitly included [27,[62][63][64], which revealed that the importance of Coriolis coupling increases with J increasing. Due to its extensive Coriolis coupling, HO 2 system served as a rigorous benchmark for helicity conserving method and Jshifting models [65][66][67][68]. Poirier et al [69][70][71] addressed approximated quantum dynamics calculations on the HO 2 bound rovibrational state using various theorybased J-shifting schemes.…”

Theoretical methods for the rotation–vibration spectra of triatomic molecules: distributed Gaussian functions compared with hyperspherical coordinates

“…However the approximation can fail for certain molecular systems. HO 2 , for example, is one of those cases in which the comparison [37][38][39] between some of these decoupling schemes and calculations performed with methods such as the ScallT program developed by Poirier and collaborators [40,41] or the Chebyshev filter diagonalization method employed by Zhang and Smith [42][43][44][45] reveals the necessity of a proper account for the Coriolis coupling terms.…”

“…Ω, and the index v Γ of the corresponding vibrational state in each irreducible representation (see Eqs. (41)(42)(43)) are given in the first, third and fourth columns, respectively. The rovibrational Γ Ω vib (fifth column), rotational Γ rot (sixth column) and total Γ (seventh column) symmetries are also indicated.…”