The average binding energy and the level width for the resonant D$^{(-)}$-state in a quantum molecule have been calculated in the presence of an external electric field. The calculations were performed in the zeroradius potential model with allowance for the tunneling decay of the resonant state. The external electric field is shown to stimulate the decay of resonant D$^{(-)}$-states under conditions of dissipative tunneling. It was found that the curve of the probability of photoionization of the D$^{(-)}$-center as a function of the external electric field strength has two peaks that are connected with a change in the symmetry of the double-well oscillator potential of the quantum molecule and with the transformation (caused by the electric field) of envelope wave functions, respectively.
$^1$Faculty of Physics, Moscow State University, Moscow, 119991, Russia
$^2$Penza State University, ul. Krasnaya 40, Penza, 440026, Russia