Hello, I'm using pwscf to generate wavefunctions for quantum Monte Carlo calculations and have run into an I/O oddity I wanted to solicit advice about. My calculations proceed as follows: scf calculation -> nscf calculation with specific k-points -> pw2casino for output. Thinking that the nscf calculation would need significantly fewer resources than the scf, I used 64 processors for the scf, 16 for the nscf and than 1 for pw2casino (I need everything written to a single file at the end). In order for this to work, I specified wf_collect=.true. in both the scf and nscf input files. Both of those tasks completed without incident but pw2casino died with an I/O error (unable to read file). However, I rerun everything using the same number of processors for scf and nscf, and only having wf_collect=.true. in the second step, everything runs perfectly.
Looking into the output directory I notice two things. When I have wf_collect in both files, I still end up with 64 .wfc* files in the directory as well as having directories for all of the k-points from the scf calculation in the outdir/prefix.save/ directory. Is it possible this is confusing pw2casino? Is there some way this problem could be remedied or am I making some logical mistake with the way I'm attempting to use the code? Thanks, Luke Shulenburger Geophysical Laboratory Carnegie Institution of Washington (lshulenburger at ciw.edu)