export OMP_NUM_THREADS=2 mpirun -np 16 vasp_std # 16 MPI ranks, each with 2 OpenMP threads Adjust for your node's core count. Ensure your makefile.include uses fft3dlib.o from VASP’s own library, not generic FFTW. The template above already uses the optimized internal FFT. 3. Memory optimization For large systems (>100 atoms), add to INCAR :

cp ~/software/vasp.5.4.4/testsuite/tests/si_base/POSCAR . cp ~/software/vasp.5.4.4/testsuite/tests/si_base/INCAR . cp ~/software/vasp.5.4.4/testsuite/tests/si_base/KPOINTS . cp ~/software/vasp.5.4.4/testsuite/tests/si_base/POTCAR_Si . mv POTCAR_Si POTCAR Run on 4 cores:

ls ../vasp_std, gam, ncl Quick test with a simple NaCl calculation Create a test directory: