In search for the negative polarizability states -: the EF1Σg+ state of hydrogen molecule

The electric polarizability of the EF (1)Sigma(g)(+) state of the hydrogen molecule is computed by means of the variation-perturbation method. The wave functions are expanded in exponentially correlated Gaussian (ECG) basis. The most accurate to date, 600-term ECG functions are employed to represent the unperturbed state and functions of similar quality are used as the first-order perturbation correction functions for parallel and perpendicular components of the dipole polarizability. In the lowest rovibrational state the computed components are 27 for the parallel and -9.6 X 10(3) a.u. for the perpendicular polarizability; consequently, the predicted total polarizability has large negative value.