Author/Authors :
McIntosh، نويسنده , , A. and Walther، نويسنده , , T. and Lucchese، نويسنده , , R.R. and Bevan، نويسنده , , J.W. and Suenram، نويسنده , , R.D. and Legon، نويسنده , , A.C.، نويسنده ,
Abstract :
The microwave spectrum and ground-state structure of H2O⋯HI are reported. The fitted ground-state constants include: A0=428.9 GHz, B0=2189.7351(5) MHz, C0=2175.9546(5) MHz, χaa=−1479.399(10) MHz, (χbb−χcc)=−17.37(1) MHz. Evidence will be presented for a complex that has an R(O–I) distance equal to 3.745(2) Å. The reduction of χaa from the value χ0 in the free HI molecule, corresponds to a zero-point oscillation angle θav=cos−1(〈cos2 θ〉1/2)=20.89(2)°. Ab initio calculations support the conclusion that the ground vibrational state for the H2O flapping mode is delocalized between two equilibrium structures at an energy above an inversion barrier.
