In general, when computing intensities for polyatomics, one has to interpolate the dipole moment function obtained from ab initio calculations. For some high overtones of the water molecule, the computed intensities can be very sensitive to the way in which the interpolation is done. Our previous... mehr

The bond energies of eight chemically bound diatomics are computed using several basis sets with and without bond functions (BF). The bond energies obtained using the aug-cc-pVnZ+BF basis sets (with a correction for basis set superposition error, BSSE) tend to be slightly smaller that the results... mehr

We report on the determination of a high quality ab initio potential energy surface (PES) and dipole moment function for water. This PES is empirically adjusted to improve the agreement between the computed line positions and those from the HITRAN 92 data base with J≤5 for H2<sup... mehr

The bond dissociation energies of CH4, C2H2, and their fragments are investigated using basis set extrapolations and high levels of correlation. The computed bond dissociation energies (De) are accurate to within 0.2 kcal/mol. The agreement with the experimental (D0) values is excellent if we... mehr

The singlet and triplet states of AlCu and AlAg below about 32 000 cm−1 are studied using the internally contracted multireference configuration-interaction method. A more elaborate study of the X 1Σ+ ground state of AlCu is undertaken using extended Gaussian basis sets, including the effect... mehr

The binding energy for the X 2Π ground state of MgO+ has been determined using the coupled-cluster singles and doubles approach with a perturbational estimate of the triples and the modified coupled-pair functional approach in conjunction with very large basis sets. Our best value of 2.32±0.06... mehr

Copyright: Copyright (c) 2002 Elsevier Science B.V. mehr

The lowest 5Π and 5Σ+ states of CO are characterized using very large one-particle basis sets and the internally contracted multireference configuration–interaction treatment of electron correlation. It is found that the (1)5Σ+ state is weakly bound (De=572 cm−1) with an re of 4.76 a0, in... mehr

The 1Σ+, 3Σ+, 1Π, and 3Π states of the negative ions and the 2Π and 2Σ+ states of the neutral alkali oxides are studied at high levels of theory. The calculations show that ground state of the negative ions changes from 3Π for LiO− to 1Σ+ for KO−. Although the calculations give a 3Π... mehr