Annie Spielfiedel

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We present two new two-dimensional potential-energy surfaces for the SO-He system calculated at SO r distance frozen at its experimental minimum-energy distance. Both are obtained at the RCCSD(T) level using two different basis sets (AVTZ and AVQZ) for the three atoms. Bond functions are placed at mid-distance between the SO center of mass and He for a(More)
We compute a new potential energy surface (PES) for the study of the inelastic collisions between N2H(+) and H2 molecules. A preliminary study of the reactivity of N2H(+) with H2 shows that neglecting reactive channels in collisional excitation studies is certainly valid at low temperatures. The four dimensional (4D) N2H(+)-H2 PES is obtained from(More)
The BASECOL2012 database is a repository of collisional data and a web service within the Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu). It contains rate coefficients for the collisional excitation of rotational, ro-vibrational, vibrational, fine, and hyperfine levels of molecules by atoms, molecules, and electrons, as well as(More)
Rotational excitation of the interstellar species SO(X3Sigma-) with H2 is investigated. The authors present a new four-dimensional potential energy surface for the SO-H2 system, calculated at an internuclear SO distance frozen at its experimental minimum energy distance. It was obtained at the RCCSD(T) level using the aug-cc-pVTZ basis sets for the four(More)
We present new theoretical calculations of the total profile of the atomic hydrogen Lyman α spectral line perturbed by collisions with neutral hydrogen atoms and protons. The variation of the radiative dipole moment during the collision is taken into account. This leads to an increase in the amplitude of the main spectral line satellites and to a(More)
Band-integrated oscillator strengths of the CO A1Π− X1Σ+ transition for 0 ≤ v′ ≤ 23 and v′′ = 0− 1 have been calculated from an ab initio dipole transition moment given by highly correlated electronic wave functions. The calculations were carefully optimized to represent the dipole transition moment in the large range of internuclear distances necessary to(More)
The SO(2) molecule is detected in a large variety of astronomical objects, notably molecular clouds and star-forming regions. An accurate modeling of the observations needs a very good knowledge of the collisional excitation rates with H(2) because of competition between collisional and radiative processes that excite and quench the different rotational(More)
The accurate highly correlated ab initio calculations for ten low lying covalent Σ+2 states of CaH molecule, and one ionic Ca+H- state, are performed using large active space and extended basis set, with special attention to the long-range (6-20 Å) region where a number of avoided crossings between ionic and covalent states occur. These states are further(More)
Rotational excitation of the CN(X (2)Sigma(+)) molecule with He is investigated. We present a new two-dimensional potential energy surface (PES) for the He-CN system, calculated at an internuclear CN distance frozen at its experimental equilibrium distance. This PES was obtained using an open-shell, coupled-cluster method including all single and double(More)
Thermal rate constants for chemical reactions using the corrections of zero curvature tunneling (ZCT) and of small curvature tunneling (SCT) methods are reported. The general procedure is implemented and used with high-quality ab initio computations and semiclassical reaction probabilities along the minimum energy path (MEP). The approach is based on a(More)