GW calculation of plasmon excitations in the quasi-one-dimensional organic compound (TMTSF)2PF6

We present an ab initio GW calculation to study dynamical effects on an organic compound (TMTSF)(2)PF6. Calculated polarized reflectivities reproduce experimental plasma edges at around 0.2 eV for E broken vertical bar broken vertical bar b' and 1.0 eV for E broken vertical bar broken vertical bar a. The low-energy plasmons come out from the low-energy narrow bands energetically isolated from other higher-energy bands, and affect the low-energy electronic structure via the GW-type self-energy. Because of the quasi-one-dimensional band structure, a distinct plasmaron state is observed along the Y-Gamma line and a large plasmon-induced electron scattering is found in the low-energy occupied states along the X-M line.