We study the dimer charge oscillations of organic charge-transfer salts in in-phase mode due to the general initial condition problem. The exact time evolution of the half-filled (two-particle) case has a complex behavior. Under certain initial conditions, the average number of fermions in one-particle state, in the half-filled case, is not necessarily periodic, even though the magnetization remains periodic. We present the expressions of the magnetization and the transition dipole moment of the organic charge-transfer salts in the in-phase mode coupled to a constant external magnetic field, for arbitrary initial conditions. We show that the constant external magnetic field plays no role in this phenomena.