E. Carmona-Novillo(a), T. González-Lezana(a), O - IFF-CSIC

THE H++D2 REACTION: A COMPARISON BETWEEN THEORY AND EXPERIMENT
E. Carmona-Novillo(a), T. González-Lezana(a), O. Roncero(a), P. Honvault(b), J.-M.
Launay(c), N. Bulut(d), F.J. Aoiz(d), L. Bañares(d), A. Trottier(e) and E. Wrede(e)
(a) IMAFF (CSIC), Serrano 123 Madrid (Spain); (b) LPM, UMR CNRS 6624 and Univ. of Franche-Comté, Campus de la
Bouloie, 25030 Besançon Cedex, (France); (c) PALMS, UMR CNRS 6627 and Univ. of Rennes 1, Campus de Beaulieu, 35042
Rennes Cedex, (France); (d) Departamento de Química Física I, Facultad de Química, Univ. Complutense, 28040 Madrid,
(Spain); (e) Department of Chemistry, Univ. of Durham, Durham, DH1 3LE (UK)
Recent experimental work [1-3] has allowed to investigate the
dynamics of the H(n)+D2 HD+D(n) reaction where H(n) is a
hydrogen atom in a highly excited Rydberg state (n~45-50). The
HD+D+
strong similitudes presented with the ion-diatom H++D2
reaction suggests that the electron of the Rydberg atom behaves as
a spectator. Analogously to a previous study on the H++H2(v=0,j=0)
process [4], the dynamics of the H++D2(v=0,j=0) reaction on the
potential energy surface by Aguado et al. [5] has been theoretically
analysed by means of a time-independent exact quantum mechanical
(EQM) method [6], a quantum wave packet (QWP) approach [7], a
statistical quantum model (SQM) [8] and a quasi-classical trajectory
(QCT) method [9]. A detailed comparison with previous experimental
data at the Ec = 0.524 eV collision energy has been completed with
Ec = 0.524
eV
theoretical
predictions at a lower energy, Ec = 0.1 eV, in an attempt
to observe possible changes on the reaction mechanism.
→
+
+
H +D2(v=0,j=0) → HD+D
Probability
→
EQM
QCT
SQM
QWP
0.5
Ec = 524 meV
0.0
3
2
Ec=0.524 eV
1
0
20
40
60
80
100
10
20
25
30
35
40
45
50
120
140
15
10
5
0
01
2
3
CM scattering angle (deg.)
5
15
20 Θ =17 deg
lab
15
10
5
+
Signal [arb. units]
2
DCS [Å /sr]
2
DCS [Å /sr]
20
EQM
SQM
QCT
EXP
QWP
0
Total angular momentum, J
25
4
+
H +D2(v=0,j=0) → HD+D
1.0
4
0
5
6
7
0.6
8
4
*2
0.5
0.4
0.3
0.2
10
Θlab=32 deg
0
20
40
60
80
100
120
140
160
180
Signal [arb. units]
0
CM scattering angle (deg.)
EQM
SQM
QCT
EXP
QWP
2
0.2
j'=1
4
Ec=0.524 eV
0.3
2
j'=0
2
0.4
DCS [Å /sr]
DCS [Å /sr]
2
DCS [Å /sr]
4
3
0.2
0.1
2
0.0
1
0
0
30
30
60
60
90
angle [deg]
90
120
0.0
120
30
60
90
120
150
CM scattering angle [deg]
5
0
angle [deg]
0
180 0
01
2
3
H* + D2(1, j' )0
30
60
90
120
EXP
QCT
SQM
EQM
150
180
0.6
CM scattering angle [deg]
4
5
6 HD(0, j' ) + D* 7
0.5
8
4
*2
0.4
0.3
0.2
D atom kinetic energy [eV]
1.0
Ec = 0.1 eV
EQM
SQM
QCT
QWP
0.6
+
70
60
2
Probability
0.8
+
DCS [Å /sr]
+
H +D2(v=0,j=0) → HD+D
0.4
0.2
50
40
H +D2(v=0,j=0) → HD(v'=0)+D
Ec=0.1 eV
+
References
EQM
SQM
QCT
QWP
30
20
10
0.0
0
5
10 15 20 25 30
Total angular momentum, J
0
0
30
60
90 120 150
CM scattering angle (deg.)
180
[1] D. Dai et al., Phys. Rev. Lett. 95, 013201 (2005).
[2] E. Wrede et al., Phys. Chem. Chem. Phys. 7, 1577 (2005).
[3] H. Song et al., J. Chem. Phys. 123, 074314 (2005).
[4] T. González-Lezana et al., J. Chem. Phys. 125, 094314 (2006).
[5] A. Aguado et al., J. Chem. Phys. 112, 1240 (2000).
[6] P. Honvaul et al., In Theory of Chemical Reaction Dynamics, Laganá A,,
Lendvay G., Eds.; Kluwer: Dordrecht, The Netherlands (2004).
[7] T. González-Lezana et al. J. Chem. Phys. 123, 194309 (2005).
[8] E.J. Rackham et al., Chem. Phys. Lett. 343, 356 (2001); E.J. Rackham et
al., J. Chem. Phys. 119, 12895 (2003).
[9] F.J. Aoiz et al., J. Chem. Soc. Faraday Trans. 94, 2483 (1998).