Run the verbs or ibverbs version of NAMD as on any other cluster, using poe in place of mpiexec as the process launcher, for example:
charmrun +p<procs> ++mpiexec-no-n ++remote-shell poe namd3 <configfile>
The details of job submission will vary between sites. For example, two nodes with two tasks per node on LSF are -n 4 -R "span[ptile=2]" with charmrun options +p36 ++ppn 9 ++mpiexec-no-n ++remote-shell poe