  A new type of charge-ordering pattern for Pr1-xCaxMnO3: a hybridization of
site- and bond-centred ordering (SBCO) was proposed by Efremov et al.. It was
believed this discovery opened a new route to magnetic ferroelectrics. Here we
argue that the possible ferroelectric of Pr1-xCaxMnO3 also originates from the
cation displacement, similar to prototypical ferroelectric system.
