17, respectively). The populations of VP products become quite weak above
Ne
35 Cl 2 (B, v B > 16) [25].
Calculations carried out in [25] show the following:
– The NeCl 2 (B, v B !
3 P(2 g )) ! Ne + 2Cl(
2 P 3/2 ) electronic predissociation (EP)
channel opens at v B = 13 (Fig. 6.2);
The Ne
35 Cl 2 (B, v B ) ! Ne + Cl 2 (B,v B -Dv B ) VP channel dominates at Ne
35 Cl 2 (B,
low v B ), but the Dv B = 1 channel becomes energetically impossible with v B
increasing due to strong Cl 2 (B, v B ) anharmonicity. In this case, the Dv B = (2 Ä 5)
channels become appreciable due to intramolecular vibrational redistribution (relaxation) (IVR): the decay occurs predominantly in a stepwise fashion:
NeCl 2 B; v B ; n
i
B ! B; v B À1 ; n
f
B
! Ne þ Cl 2 B; v B À Dv B
ð
Þ ;
ð6:3:1Þ
Dv B > 1, n
f
B is more than the initial vdW quantum number, n
i
B . The IVR results
from quasi-degeneracy between the initial excited NeCl 2 (B, v B , n
i
B ) state (‘bright
state’) and intermediate zero-order NeCl 2 (B, v B -1, n
f
B ) ‘dark states’ with less
Cl 2 (B) vibrational excitation and more vdW energy, NeCl 2 (B, v B -1, n
f
B ). The
vibrational coupling induced by the neon atom mixes these zero-order
quasi-degenerate states, which leads to a population to the dark state. It, in turn,
decay to the Ne + Cl 2 (B, v B - Dv B ), Dv B = (2 Ä 5) (Fig. 6.3), see Sect. 6.4.3.2 in
[18], [62, 63] and references.
IVR realized in so-called ‘sparse’, ‘intermediate’, and ‘statistical’ regimes for
which half-widths of the bound ArI 2 (B, v B , n B ) levels are much less, comparable,
10
15
20
0,0
0,2
0,4
EP probability
ν B
Fig. 6.2 The NeCl 2 (B,v B ) EP probability as a function of v B (see [25]) (Reprinted with permission
C. R. Bieler, K .C Janda, R. Hernández-Lamoneda, O. Roncero, NeCl 2 and ArCl 2 : Transition from
direct vibrational predissociation to intramolecular vibrational relaxation and electronic nonadiabatic effects. J. Phys. Chem. A. 114, 3050–3059 (2010). https://doi.org/10.1021/jp906392m.
Copyright 2010 American Chemical Society)
6.3 Van der Waals Complexes
207
Ne
35 Cl 2 (B, v B > 16) [25].
Calculations carried out in [25] show the following:
– The NeCl 2 (B, v B !
3 P(2 g )) ! Ne + 2Cl(
2 P 3/2 ) electronic predissociation (EP)
channel opens at v B = 13 (Fig. 6.2);
The Ne
35 Cl 2 (B, v B ) ! Ne + Cl 2 (B,v B -Dv B ) VP channel dominates at Ne
35 Cl 2 (B,
low v B ), but the Dv B = 1 channel becomes energetically impossible with v B
increasing due to strong Cl 2 (B, v B ) anharmonicity. In this case, the Dv B = (2 Ä 5)
channels become appreciable due to intramolecular vibrational redistribution (relaxation) (IVR): the decay occurs predominantly in a stepwise fashion:
NeCl 2 B; v B ; n
i
B ! B; v B À1 ; n
f
B
! Ne þ Cl 2 B; v B À Dv B
ð
Þ ;
ð6:3:1Þ
Dv B > 1, n
f
B is more than the initial vdW quantum number, n
i
B . The IVR results
from quasi-degeneracy between the initial excited NeCl 2 (B, v B , n
i
B ) state (‘bright
state’) and intermediate zero-order NeCl 2 (B, v B -1, n
f
B ) ‘dark states’ with less
Cl 2 (B) vibrational excitation and more vdW energy, NeCl 2 (B, v B -1, n
f
B ). The
vibrational coupling induced by the neon atom mixes these zero-order
quasi-degenerate states, which leads to a population to the dark state. It, in turn,
decay to the Ne + Cl 2 (B, v B - Dv B ), Dv B = (2 Ä 5) (Fig. 6.3), see Sect. 6.4.3.2 in
[18], [62, 63] and references.
IVR realized in so-called ‘sparse’, ‘intermediate’, and ‘statistical’ regimes for
which half-widths of the bound ArI 2 (B, v B , n B ) levels are much less, comparable,
10
15
20
0,0
0,2
0,4
EP probability
ν B
Fig. 6.2 The NeCl 2 (B,v B ) EP probability as a function of v B (see [25]) (Reprinted with permission
C. R. Bieler, K .C Janda, R. Hernández-Lamoneda, O. Roncero, NeCl 2 and ArCl 2 : Transition from
direct vibrational predissociation to intramolecular vibrational relaxation and electronic nonadiabatic effects. J. Phys. Chem. A. 114, 3050–3059 (2010). https://doi.org/10.1021/jp906392m.
Copyright 2010 American Chemical Society)
6.3 Van der Waals Complexes
207