<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div>Dear All,</div><div><br></div><div>I know that in previous versions of QE, wavefunctions are stored as evc.dat in each K**** directory within the prefix.save directory, and eigenvalues are stored as eigenval.xml. I know how to use the iotk library to read those files. In the new version of QE, I saw that the wavefunctions and the eigenvalues are stored as wfc*.dat within the prefix.save directory. I don't know how to use the iotk library to read these anymore. In particular, I don't know the XML tag structures (if any) associated with these wfc*.dat files (if I vi them, I don't see those - in the previous versions, even the files are binary but the tags are visible as ascii). If there are no tag structures as the old format, how do I read those files? I do know about one possible solution: use pw_export.x to convert those wfc*.dat to XML format and then everything is just normal for iotk. However I am hesitating to do this because some of my wavefunctions are hundreds of GBs and the pw_export.x takes time and a lot of disk space. If there is a better way to directly read those wfc*.dat files, I would appreciate it.</div><div><br></div><div>By the way, the pertinent information seems to be missing in the developer's manual (as of v6.4), and in that manual the data structure is still described as evc.dat and eigenval.xml as the old QE version, which I don't think is the case for the current version.</div><div><br></div><div>Best regards,</div><div><br></div><div><br></div><div>Zhenfei</div></div></body></html>