Theoretical rotation-torsion spectra of HSOH.
Rotation-torsion spectra of HSOH, involving the vibrational ground state and the fundamental torsional state, have been simulated at T = 300 K. The simulations are carried out with the variational computer program TROVE in conjunction with recently reported ab initio potential energy and electric dipole moment surfaces. HSOH is a near-prolate-symmetric top at equilibrium and the simulated spectra are of perpendicular-band-type with strong R-branch and Q-branch transitions. Recently, an anomalous (b-type-transition)/(c-type-transition) intensity ratio in the vibrational-ground-state (r)Q(K(a))-branches of HSOH has been experimentally observed. Our calculations reproduce correctly the anomaly and show that it originates in the large-amplitude torsional motion of HSOH. We analyze our theoretical results in order to explain the effect and to provide unambiguous (b/c)-type-transition assignments.
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Andrey
A
Yachmenev
Sergei N
SN
Yurchenko
Per
P
Jensen
Oliver
O
Baum
Thomas F
TF
Giesen
Walter
W
Thiel
D003198:Computer Simulation; D010545:Peroxides / Q000737:chemistry*; D011789:Quantum Theory; D012399:Rotation; D012984:Software; D014732:Vibration
D010545:Peroxides; C552843:hydrogen thioperoxide