Calculated energies seem to explode (<etotal> grows exponentially) whenever the number of threads per task is greater than 1, at least on cab. Setting OMP_NUM_THREADS to 1 via export OMP_NUM_THREADS=1 avoids the issue.
The input script we were using was:
set ecut 45
set cell 15.0 0.0 0.0 0.0 15.0 0.0 0.0 0.0 15.0
species H H_HSCV_PBE-1.0.xml
atom H1 H 1.508729 0.441434 0.259102
set force_complex_wf ON
set xc PBE
set ecutprec 8.0
randomize_wf
run 0 500
quit