  The relaxation effects in the perturbed angular correlation spectra of
indium-111 human carbonic anhydrase I (HCA I) are the result of chemical
transmutation and/or the complex Auger cascades that follow the electron
capture decay of indium-111. Time differential K X ray coincidence perturbed
angular correlation (PAC) spectroscopy shows that these relaxation effects are
independent of the Auger cascade intensity. This suggests that chemical
transmutation is responsible for the relaxation effects, and that bond breaking
and damage product formation around the decay site resulting from localized
energy deposition by Auger and Coster-Kronig electrons probably occur in the
microsecond time regime. Numerical simulations of chemical transmutation
relaxation effects in the time differential PAC spectrum of indium-111 HCA I
are also presented.
