Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA.
Phys Chem Chem Phys. 2011 Nov 14;13(42):19026-35. doi: 10.1039/c1cp21494b. Epub 2011 Jul 29.
Close-coupling calculations of the resonance and near resonance charge exchange in ion-atom collisions of Be at low and intermediate energies are presented. Accurate ab initio calculations are carried out of the Born-Oppenheimer potentials and the non-adiabatic couplings that are due to the finite nuclear masses and drive the near resonance charge exchange. We show that the near resonance charge exchange cross section follows Wigner's threshold law of inelastic processes for energies below 10(-8) eV and that the zero temperature rate constant for it is 4.5 × 10(-10) cm(3) s(-1). At collision energies much larger than the isotope shift of the ionization potentials of the atoms, we show that the near resonance charge exchange process is equivalent to the resonance charge exchange with cross sections having a logarithmic dependence. We also investigate the perturbation to the charge exchange process due to the non-adiabatic interaction to an electronic excited state. We show that the influence is negligible at low temperatures and still small at intermediate energies despite the presence of resonances.
呈现了 Be 离子与原子在低能和中能区共振和近共振电荷交换的紧密耦合计算。对 Born-Oppenheimer 势能和非绝热耦合进行了精确的从头算，这些非绝热耦合是由有限的核质量引起的，并驱动近共振电荷交换。我们表明，近共振电荷交换截面遵循 Wigner 关于非弹性过程的阈值定律，对于低于 10(-8) eV 的能量，其零温度速率常数为 4.5 × 10(-10) cm(3) s(-1)。在远大于原子电离势同位素位移的碰撞能量下，我们表明近共振电荷交换过程等效于共振电荷交换，其截面具有对数依赖性。我们还研究了非绝热相互作用对电荷交换过程的微扰。我们表明，在低温下影响可以忽略不计，尽管存在共振，但在中等能量下仍然很小。
