I meet one questions about the link atom in DNA. When I want to add the link atom between N1 (QM) and C1' (MM) in CYT of DNA, the mass of C1' in the psf file of this CYT becomes 11.0030. While the link atoms are added between C5' and O5', the mass of C1' is 12.0100.
Plaese give your suggestions, comments and hints. Thanks.