  We propose a model to account for the bolometric light curve, quasi-continuum
and the Ca II emission features of the peculiar type Ia supernova (SN) 2002ic,
which exploded in a dense circumstellar envelope. The model suggests that the
SN Ia had the maximum possible kinetic energy and that the ejecta expand in an
approximately spherically symmetric (possibly clumpy) circumstellar
environment. The Ca II and quasi-continuum are emitted by shocked SN ejecta
that underwent deformation and fragmentation in the intershock layer. Modeling
of the Ca II triplet implies that the contribution of the O I 8446 A line is
about 25% of the 8500 A feature on day 234, which permits us to recover the
flux in the Ca II 8579 A triplet from the flux of 8500 A blend reported by Deng
et al. (2004). We use the Ca II doublet and triplet fluxes on day 234 to derive
the electron temperature (~4400 K) in the Ca II line-emitting zone and the
ratio of the total area of dense fragments to the area of the shell, S/S_0 ~
100. We argue that Ca II bands and quasi-continuum originate from different
zones of the shocked ejecta that reflect the abundance stratification of the
supernova.
