A new potential energy surface and predicted infrared spectra of He-CO2: dependence on the antisymmetric stretch of CO2.
A new potential energy surface involving the antisymmetric Q(3) normal mode of CO(2) for the He-CO(2) van der Waals complex is constructed at the coupled-cluster singles and doubles with noniterative inclusion of connected triple [CCSD(T)] level with augmented correlation-consistent quadruple-zeta (aug-cc-pVQZ) basis set plus bond functions. Two vibrationally adiabatic potentials with CO(2) at both the ground and the first excited vibrational states are generated from the integration of the three-dimensional potential over the Q(3) coordinate. The potential has a T-shaped global minimum and two equivalent linear local minima. The bound rovibrational energy levels are obtained using the radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm. The observed band origin shift of the complex (0.0946 cm(-1)) is successfully reproduced by our calculation (0.1034 cm(-1)). The infrared spectra of the complex are also predicted. The fundamental band is in excellent agreement with the experiment. Most of the transitions corresponding to the observed hot band [M. J. Weida et al., J. Chem. Phys. 101, 8351 (1994)] are assigned reasonably.
Ran
Hong
H
Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Xie
Daiqian
D