  A mayor problem that arises in the computation of stellar atmosphere models
is the self consistent determination of the temperature distribution via the
constraint of energy conservation. The energy balance includes the gains due to
the absorption of radiation and the losses due to emission. It is well known
that within each one of the two above integrals the part corresponding to
spectral ranges whose opacity X(nu) is huge can overcome by many orders of
magnitude the part that corresponds to the remaining frequencies. On the other
hand, at those frequencies where X(nu) is very large, the mean intensity J(nu)
of the radiation field shall be equal, up to many significant digits, to the
source function S(nu) and consequently to the Planck function B(nu,T). Then
their net share to the energy balance shall be null, albeit separately their
contributions to the gain and loss integrals are the most important
numerically. Thus the spectral range whose physical contribution to the overall
balance is null will dominate numerically both sides of the energy balance
equation, and consequently the errors on the determination of J(nu) and S(nu)
at these frequencies will falsify the balance.
  It is possible to circumvent the numerical problem brought about by the
foregoing circumstances by solving the radiative transfer equation for the
variable I(n,nu) - S(nu), instead of the customary intensity I(n,nu).
  We present here a novel iterative algorithm, based on iteration factors
already employed by us with success, which makes it possible a fast correction
of the temperature by computing directly the difference between the radiative
losses and gains at each step of the iterations.
