fix header

docs/Scientific_Computing/Supported_Applications/GROMACS.md

@@ -1,4 +1,4 @@
 ---
 created_at: '2019-02-21T02:46:25Z'
 tags: 
   -  molecular dynamics
@@ -19,13 +19,13 @@
 
 It is primarily designed for biochemical molecules like proteins, lipids
 and nucleic acids that have a lot of complicated bonded interactions,
 but since GROMACS is extremely fast at calculating the nonbonded
 interactions (that usually dominate simulations) many groups are also
 using it for research on non-biological systems, e.g. polymers.
 
 GROMACS is available to anyone at no cost under the terms of 
 [the GNU Lesser General Public Licence](http://www.gnu.org/licenses/lgpl-2.1.html). 
 Gromacs is a joint effort, with contributions from developers around the world: users agree
 to acknowledge use of GROMACS in any reports or publications of results
 obtained with the Software.
 
@@ -121,17 +121,17 @@
 
 GROMACS is built with CUDA support, but that is optional to use - it will run without a GPU.
 
-### MPI
+## MPI
 
 If you do elect to use `gmx-mpi`, note that hybrid parallelisation (i.e. with `--cpus-per-task` > `1`) can be
 more efficient than MPI-only parallelisation.  With hybrid parallelisation, it is important to run
 `mdrun_mpi` with the `-ntomp <number>` option, where `<number>` should
 be the number of CPUs per task. You can make sure the value is correct
 by using `-ntomp ${SLURM_CPUS_PER_TASK}`. 
 
 ## Checkpointing
 
 The `-cpt 30` option instructs Gromacs to
 write a full checkpoint file every 30 minutes.
 
 We reccomend including this flag for long running jobs.