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
and we describe the covalent potential only by two terms:
where the potential parameters are given in table A08-m4bii1-T1
| = 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
| = 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.