V Chernyak, Wei Min Zhang, S Mukamel, J Chem Phys Vol. 109, 9587 (can download here http://mukamel.ps.uci.edu/publications/pdfs/347.pdf ) Eq.(2.2), Eq. (B1) Eq.(B4)-(B6). When I substitue Eq.(B4)-(B6) into Eq.(2.2), I can not recover Eq.(B1). Who can give me a reference or hint on how to write electron hole Hamiltonian into quasi-boson operator? I think it is not possible to write sole electron or sole hole Hamiltonian in Eq.(2.2) into quasi-boson operator. Eq.(2.2) describes a two-band (one conduction one-valence semiconductor) system in real space, taking account of electron-electron, hole-hole, electron-hole interactions.