Autor: |
Kłos, Jacek, Hapka, Michał, Chałasiński, Grzegorz, Halvick, Philippe, Stoecklin, Thierry |
Předmět: |
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Zdroj: |
Journal of Chemical Physics; 2016, Vol. 145 Issue 21, p1-10, 10p, 1 Diagram, 3 Charts, 9 Graphs |
Abstrakt: |
We present a theoretical study of the Zeeman relaxation of the magnetically trappable lowest field seeking state of CrH(X6∑+) in collisions with ³He. A two dimensional potential energy surface (PES) was calculated with the partially spin-restricted coupled cluster singles, doubles, and non-iterative triples [RCCSD(T)] method. The global minimum was found for the collinear He ... Cr-H geometry with the well depth of 1143.84 cm-1 at Re = 4.15 a0. Since the RCCSD(T) calculations revealed a multireference character in the region of the global minimum, we performed additional calculations with the internally contracted multireference configuration interaction with the Davidson correction (ic-MRCISD+Q) method. The resulting PES is similar to the RCCSD(T) PES except for the region of the global minimum, where the well depth is 3032 cm-1 at Re = 3.8 a0. An insight into the character of the complex was gained by means of symmetry-adapted perturbation theory based on unrestricted Kohn-Sham description of the monomers. Close coupling calculations of the Zeeman relaxation show that although the ΔMJ = M'J -MJ = -1 and -2 transitions are the dominant contributions to the collisional Zeeman relaxation, ΔMJ < -2 transitions cannot be neglected due to the large value of CrH spin-spin constant. The calculated elastic to inelastic cross section ratio is 1600 for the RCCSD(T) PES and 500 for the MRCISD+Q PES, while the estimate from the buffer-gas cooling and magnetic trapping experiment is 9000. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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