Electronic states of the FO radical. An MRSDCI study

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.