What is MRBAYES?
A program for Bayesian inference and model choice across a wide range of phylogenetic and evolutionary models. MrBayes uses Markov chain Monte Carlo (MCMC) methods to estimate the posterior distribution of model parameters.
To run mrbayes in MPI mode, execute (or add this line to PBS job command file):
mpirun /share/bin/mb MRBAYES_BATCH_FILE
It is reminded that you need to include the mrbayes_batch_file and the NEX files in the same directory. A sample PBS job command file can be copied from /share/mrbayes/pbs-mb.cmd and a sample mrbayes batch file can be found at /share/mb/run_mb_batch.
Official documentation can be obtained from MRBAYES Documentation