There are two main benchmark scripts here:

1.  A molecular dynamics run (bench_md.nab), which just times first-derivative
    code.  This does 100 steps of dynamics; change to a larger value if
    this is too short a benchmark.

2.  A Newton-Raphson minimization (bench_nr.nab), which exercises the second-
    derivative routines.  This does 5 cycles of Newton-Raphson; again, change
    to a larger value for a longer benchmark.

To compile and run, do this:

       nab bench_md.nab   [ or  nab bench_nr.nab ]
       ./a.out <tag>   

Here <tag> is one of the following:
      gcn4p1    ( 1084 atoms )
      gcn4dna   ( 3227 atoms )
      1akd      ( 6370 atoms )
      halfam0   ( 9515 atoms )

      gact3     ( 2854 atoms -- DNA )
      gact4     ( 3806 atoms -- DNA )

Note: the "bench_amber" script will run the same thing as bench_md.nab
      program, so facilitate comparisons between Amber and NAB.
