I am trying to compute the non-linear susceptibility for a system with 64 atoms. After some initial trouble, things seem to be going well, but as I expected it is taking a long time to compute all of the derivatives. My calculation is now in dataset 4 (see below) and I can see that multiple density and wavefunction files have been (are being) written to disk. The last few are also listed below for reference. Unfortunately, I have to stop the machine for some maintenance tomorrow and I am wondering if I can resume the calculation from dataset 4 and read in the already completed results and/or change the range of derivates calculated to just do the missing pieces. This might be a tall order and not easily possible (but it is easy to ask!). I suspect that the calculation has taken a couple of weeks to get this far. It would be nice to throw more cores at the problem to speed it up, but when I tried 96 cores instead of the current 64, the program has a mysterious crash (likely too many cores for the algorithm). Any suggestions as to how to optimize things would be appreciated.
#####################
##### DATASET 4 #####
#####################
##############################################
#### SECTION: basic
##############################################
kptopt4 3
tolvrs4 1e-12
##############################################
#### SECTION: dfpt
##############################################
optdriver4 1
rfphon4 1 # compute 1st-order WF derivatives with respect to atomic displacements
rfelfd4 3 # compute 1st-order WF derivatives with respect to electric field
rfstrs4 3 # compute 1st-order WF derivatives with respect to strains
prepanl4 1 # make sure that response functions are correctly prepared for a non-linear computation
##############################################
#### SECTION: files
##############################################
getwfk4 2 # use GS WF from dataset 2
getddk4 3 # use ddk WF from dataset 3 (needed for electric field)
prtwf4 1 # save 1st-order WF on disk, will be used in other datasets
prtden4 1 # save 1st-order density on disk, will be used in other datasets
-rw-r--r-- 1 10001 10002 5.0G Oct 11 17:02 outnc_DS4_1WF58.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 17:01 outnc_DS4_POT58.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 17:01 outnc_DS4_DEN58.nc
-rw-r--r-- 1 10001 10002 5.0G Oct 11 14:23 outnc_DS4_1WF57.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 14:22 outnc_DS4_POT57.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 14:22 outnc_DS4_DEN57.nc
-rw-r--r-- 1 10001 10002 5.0G Oct 11 11:15 outnc_DS4_1WF56.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 11:14 outnc_DS4_POT56.nc
-rw-r--r-- 1 10001 10002 15M Oct 11 11:14 outnc_DS4_DEN56.nc
.... many more a total of 191 files so far