The non-Markovian encounter theory is reformulated and used to find th
e quantum yields and kinetics of reversible energy transfer. Assuming
a short range interaction between the particles, the kinematic approxi
mation is employed to determine the integral kinetic equations and fol
lowing from them differential equations of encounter theory. The diffe
rential variant of the theory is shown to be less appropriate since it
fails to describe delayed luminescence during encounter: The reaction
constant diverges with time when the acceptor of energy decays slower
than the energy donor. On the contrary, integral encounter theory is
very suitable for calculating the quantum yields and dissipation kinet
ics at any ratio between decay times. (C) 1995 American Institute of P
hysics.