  We present the current status of PHOENIX model atmospheres for dwarfs of the
spectral type T, typical for older field brown dwarfs and low-mass brown
dwarfs. The results are based on new predictions of the CH_4 line opacities
from theoretical calculations with the STDS software package, extrapolating to
transitions from rotational levels up to J=40. While individual line positions
and strengths are reproduced with moderate to fair accuracy, the cumulative
band strength in the region of the IR methane bands is modelled much better
thanks to the inclusion of large numbers of faint lines relevant at high
temperatures.
