Fix crash when parsing DOSCAR files containing no partial DOS data (e.g. NaCl).
Fix crash when parsing DOSCAR files containing no partial DOS data (e.g. NaCl).

Previously tried to subtract Fermi energy from energy values in a
nonexistent list of partial DOS. Now checks if the list exists.

rartino/ENVISIoN,rartino/ENVISIoN,rartino/ENVISIoN,rartino/ENVISIoN,rartino/ENVISIoN,rartino/ENVISIoN