  In recent years, researchers have discovered various excited states of
electrons having an excited domain with a structural order different from the
original one. We examine a dynamics of electron system and phonon system by
using the time-dependent Hartree-Fock approximation. We examine time evolution
with spin degree of freedom. We found a thermally excited
paraelectric-to-ferroelectric crossover. The metastable state is spin pierls
state. We also examine the Landau expansion of electron system at
quarter-filled.
