Theoretical study of the dipole moment of oxygen monofluoride (OF)

Quantum Interference Contribution to the Dipole Moment of Diatomic Molecules

The interference energy partitioning analysis method developed by our group and used to study the nature of the chemical bond was extended to partition the electric dipole moment in quasi-classical and interference contributions. Our results show that interference participates in charge displacement in polar molecules, providing, directly or indirectly, a relevant contribution for the total dipole moment. A linear correlation was found between the interference contribution of the dipole moment from the bond electron group, μ_INT(bond), and the difference of electronegativity of the atoms which form the bond, ΔX_AB. This interesting result reinforces the fact that electronegativity is not a property of an atom alone, but rather a property of the atom in the molecule and that ΔX_AB can only be associated with that part of the total charge displacement resulting from the formation of the chemical bond. The partitioning of the total dipole moment into quasi-classical and interference contributions provides new insights about the reasons for the failure of the ΔX_AB criterion in predicting the correct orientation of the dipole moment in several molecules. The results of the present work also bring additional evidence for the previously proposed mechanism of formation of polar bonds.

Theoretical study on the ground electronic state of FO(+) and FO(-)

The equilibrium structures of the ground electronic states for molecular ions FO(+) and FO(-) have been calculated by using the multi-reference configuration interaction method in combination with the augmented correlation-consistent basis sets up through sextuple zeta quality. The equilibrium parameters, potential energy curves and spectroscopic constants are derived for both species. The extrapolation schemes are adopted to estimate the complete basis set limit. The corrections of core-valence correlation and relativistic effect are included to improve the accuracy of the calculations. The vibrational energy levels as well as rotational and centrifugal distortion constants of the ground electronic states for both systems are obtained by solving the radial Schrödinger equation of nuclear motion. The computations on neutral FO radical are also carried out to investigate the ionization potentials and the electron affinities.

The X(1)(2)Pi(3/2) and X(2)(2)Pi(1/2) Potential Energy Surfaces of FO

The X(1)(2)Pi(3/2) and X(2)(2)Pi(1/2) potential energy curves of the FO free radical have been determined from a fit to the available high-resolution spectroscopic data. The data set spans the vibrational states v = 0-7 and includes X(2)(2)Pi(1/2) <-- X(1)(2)Pi(3/2) fine-structure transitions. The determinable spectroscopic constants provide an excellent description of the equilibrium properties of both the X(1) and X(2) states in addition to the vibrational dependence of the spin-orbit coupling constant. The experimental properties of FO are used to evaluate the performance of different ab initio methods for describing the F-O bond. Copyright 2001 Academic Press.