Single-Valued DMBE Potential Energy Surface for HSO:  A Distributed n-Body Polynomial Approach

Abstract

An accurate single-valued double many-body expansion (DMBE) potential energy surface is reported for the ground electronic state of HSO based on novel MR CISD ab initio energies suitably corrected for the complete one-electron basis set/complete CI limit. To improve the accuracy of the fit, we have suggested a n-body distributed polynomial approach which implies using individual multinomial developments at the various stationary points. For simplicity, only the three most relevant such points have been considered: two minima (HSO, HOS) and the saddle point connecting them.

Potential Energy Surface for Ground-State H2S via Scaling of the External Correlation, Comparison with Extrapolation to Complete Basis Set Limit, and Use in Reaction Dynamics

“…Then, by removing the three-body dc part described in eq 12 from the total three-body energy, the three-body EHF energy is obtained. This is finally modeled by using the following three-body distributedpolynomial 34 form…”

Accurate DMBE Potential Energy Surface For the N(2D) + H2(1Σ g + ) Reaction Using an Improved Switching Function Formalism

“…(17), one gets the three-body extended Hartree-Fock energy. This has been modeled via a threebody distributed-polynomial [36] form …”

“…where all the polynomials P ( j) (Q 1 , Q 2 , Q 3 ) are written in terms of symmetry coordinates (for definition of the latter, see, [36]). Note that all polynomials are of sixth order, except the fifth one which is of fourth order.…”

Dinámica de reacciones unimoleculares en fase gas: Desviaciones del comportamiento estadístico

“…Dentro de estas aproximaciones es especialmente intuitiva y útil la expansión doble de multicuerpos (DMBE) con el que uno de los autores y Varandas han desarrollado una SEP para el HSO 111 . Sin embargo, cuando el número de átomos es mayor resulta más adecuado el empleo de técnicas de dinámica directa.…”