[Legenda] [Contentsof the thesis] [Comments on this module] [Legenda] [Contentsof the thesis] [Comments on this module]

## Treated results: Potential and deflection function=A08-m4bii1

The sodium-iodine potential curves are given by the following expressions. The ionic ground state is usually described by the Rittner potential

 = (E2)

and we describe the covalent potential only by two terms:
 , (E2)
where the potential parameters are given in table A08-m4bii1-T1 .

 Ionic-potential parameters Covalent-potential parameters = 0.4083.a = 273.h = 6.4313.a = 73.i Cion = 11.3 eV6.b Ccov =1000 eV6.j Aion = 1913.6 (2760l) eV.c Acov =3150 eV .j = 0.3489.d =0.435 .j = 3.11 + eV.e re = 2.71143 (2.664l).f Coupling parameters = 2.075eV.g H12 = 0.065 eV (0.0024 a.u. k) Hrot = 3 x 10-17 (0.04 a.u. k) a Dipole polarizability, . b Van der Waals coefficient, from the London formula: , where I2 is the second ionization potential of Na and A is the electron affinity of I. c . d . e Potential well depth, . f Internuclear equilibrium distance, . g From INa-AI. h . i Arbitrary value. j From the London formula: , where I is the first ionization potential. k Present work. l Alternative value due to overdefinition of the potential curve.

 Figure A08-m4bii1_1: Na-I adiabatic potential curves. The pseudo-crossing potentials are all of the same species . .

Starting from these potential curves, the deflection function for chemi-ionisation in collisions between Na and I is given by figure A08-m4bii1-F2. The two curves due to ionic and covalent scattering are connected . Because of the several interference features, the ionic curve is split up into b, c and e branches, the covalent curve into a and d branches.
 Figure A08-m4bii1-F2: Deflection curves for chemi-ionization scattering (CM system) at Ei = 13.1 eV.