On the basis of the neutron structural analysis, lattice effect on the char
ge/orbital-ordering transition of doped manganites has been reconsidered. W
e have investigated the stability of the respective e(g) orbitals dy a Made
lung potential calculation, and have found a close correlation between the
orbital stability and the charge-ordering transition. This observation indi
cates that the chemical pressure has an aspect of orbital control, besides
the control of the transfer integral t between the neighboring Mn sites.