| Abstract: | A possibility of stabilization in an external homogeneous electric field on the HeH2(21 A′) metastable state relative to its nonadiabatic decay into the 1 1A′ state is investigated theoretically. If the lowest vibrational levels of the HeH2 (2 1A′) state might be stabilized, one would try to detect the radiative transition 1 1A′ ← 2 1A′ from these levels and thus to verify experimentally the existence of the HeH2 (2 1A′) state. It is shown that the separation between the potential energy surfaces (PESs) of the states in question and the energy of their avoided crossing point do increase in the field. Moreover, it is shown that in the fields with strength up to 107 V/cm the nonadiabatic decay of the 2 1A′ state along one of the vibrational modes may be closed. However, along two other modes such decay still may occur. It is noted nevertheless that the question of such stabilization possibility in inhomogeneous fields (i.e., in ionic crystal or on its surface) is still open. The effect of the field was taken into account within an analytic two-level model. The unperturbed PESs were calculated by the CASSCF method. © 1996 John Wiley & Sons, Inc. |
