Time of loss of a specified accuracy of semiclassical trajectory-coherent states

The concept of the effective time of loss of a specified accuracy of an approximate solution of a wave equation is introduced. It is shown that in the case of motion of a particle in a constant homogeneous magnetic field this time is comparable with the time of one gyration of the particle. In the case of motion in electric fields, the accuracy may increase with increasing time, and effective loss will not occur.