We briefly review the key ideas and important physical approximations
which are used to derive quantum dynamical equations of motion for the
spin degrees of freedom in magnetic materials. This approach to spin
dynamics uses first principles methods to obtain time and temperature
dependent magnetic properties. A new stochastic approach to simulate t
ime and temperature effects in extended spin systems is presented. Fut
ure applications and extensions are briefly covered. (C) 1997 American
Institute of Physics.