Change the scaling of npdm. Scaling of 3pdm and 4pdm is N^6M^2 + N^4M^3,
N^8M^2 +N^5M^3. (Previous scaling is N^6M^3, N^8M^3). It is used by
default for 3pdm, 4pdm, npdm_nevpt2. To close it, use
npdm_no_intermediate.