  We present perturbation initial conditions for two types of scalar field
potential often used in the dark energy study: one inverse power-law and the
other exponential. The solutions are presented in the presence of the $w =$
constant fluid ($w = 1/3$ for radiation fluid), a minimally coupled scalar
field and a sub-dominating zero-pressure fluid (cold dark matter and baryon
dust). We consider two gauge conditions, the $w$-fluid comoving gauge and the
cold-dark-matter comoving gauge; solutions in the latter gauge are derived by
the gauge transformation and this method can be applied to derive solutions in
any other gauge condition.
