Series of architectures for language modeling.

def mqp_lm1b_base():
  """Series of architectures for language modeling."""
  hparams = mtf_transformer2.mtf_unitransformer_base()
  hparams.d_model = 1024
  hparams.max_length = 256
  hparams.batch_size = 256
  # Parameters for my_layer_stack()
  hparams.num_hidden_layers = 6
  hparams.d_ff = 8192
  hparams.d_kv = 128
  hparams.num_heads = 8
  hparams.learning_rate_decay_steps = 13600
  hparams.layout = "batch:batch;vocab:model;d_ff:model;heads:model"
  hparams.mesh_shape = "batch:32"
  return hparams