Fix out of bound access
Fix out of bound access

Thanks MSVC for this one!

chemfiles/chemfiles,lscalfi/chemfiles,lscalfi/chemfiles,chemfiles/chemfiles,chemfiles/chemfiles,Luthaf/Chemharp,Luthaf/Chemharp,Luthaf/Chemharp,lscalfi/chemfiles,chemfiles/chemfiles,lscalfi/chemfiles