Konstanz 1998 – scientific programme
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MO: Molekülphysik
MO 12: Theorie: Dynamik
MO 12.6: Talk
Thursday, March 19, 1998, 12:15–12:30, M627
Ab-Initio Calculation for Ba+HBr→[BaHBr]→[BaBrH]→BaBr+H — •Victor Wei-Keh WU1, Rong-Shun ZHU2, Ke-Li HAN2, and Guo-Zhong HE2 — 1Victor Basic Research Laboratory,Bielefeld,FRG.(http://www.uni-bielefeld.de/ fkure) — 2SKLMRD, Dalian Institute of Chemical Physics, CAS. Dalian, 116023 P.R.China
The calculated results by ab initio method via Gamess90 as well as Gaussian94 with application of SBK-ECP, at RHF/UHF and MP2 levels match well the results from our QCT calculaion. Ba and HBr run a little bit easier to the nascent [Ba-H-Br] with height -0.0002264 eV, bond angle 160.38o and lengths rBaH = 6.0641 Å, rHBr = 1.4057 Å, instead of [Ba-Br-H] with height 0.0007657 eV, bond angle 51.84o and lengths rBaBr = 7.0960 Å, rBrH = 1.4055 Å, then get over the transition state [Ba-Br-H] with height 0.001156 eV, bond angle 179.52o and lengths rBaBr* = 6.9649 Å, rBrH* = 1.4056 Å. These energy levels are relative to that of reactants. The difference of ΔrBaBr* between those from QCT (1.30 Å) and ab initio (3.97 Å) are rather large. Whether the zero point energies are considered, and the ΔDoo from ab initio are 3 -5 times as large as that from QCT, don’t change the reaction path much. They can be indeed accepted, whatever fluctuation of the exp. data, and uncertainity of ab initio results because of the heavy atoms Ba and Br are thought over. The strong migration effect by H is caused by the energetical preferance between two levels for [BaHBr] instead of [BaBrH] with only 0.0008 eV. Wu acknowledges the financial aids by VBR(75%), DFG.,and SKLMRD.Ref. To be submitted.