jp068808e_si_001.txt (1.86 kB)
Equilibrium Structure of Sulfuric Acid
dataset
posted on 2007-04-05, 00:00 authored by J. Demaison, M. Herman, J. Liévin, H. D. RudolphThe equilibrium structure of the more stable conformer of H2SO4, of C2 symmetry, has been calculated ab
initio using the CCSD(T) method and taking into account the core correlation correction. The accuracy of
this structure has been checked by comparing it to that of similar molecules and by estimating the effects of
basis set enlargement and of diffuse functions. Furthermore, the quadratic, cubic, and quartic force fields
have been calculated at the MP2 level of theory using a basis set of triple-ζ quality. The spectroscopic constants
derived from the force field are in satisfactory agreement with the experimental ones. The resulting band
origins are compared to literature infrared values, including those for overtone and combination bands. Normal
modes of vibration are pictured. Using this force field, semiexperimental equilibrium rotational constants are
determined which allows us to check the accuracy of the ab initio structure and to refine it using a mixed
regression method.