Response of metal electrons to local fields of holes arising in X‐ray processes

X‐ray spectra computation methods are developed enabling allowance for metal valence band readjustment (extra‐atomic relaxation) caused by the field of a suddenly appearing finite‐lifetime hole. Allowance for the finite lifetime of the hole necessitates the introduction of a non‐hermitian perturbation Hamiltonian into the theory and, as a consequence, modification of Keldysh's technique of calculating nonequilibrium processes. The technique developed is illustrated with reference to an example of calculating the variation in time of the number of valence electrons on the site after the local field has switched on suddenly. Studying the asymptotic behaviour of that quantity allows one to determine the intensity of the satellite structure of inner‐level X‐ray photoelectron spectra.