  We present a total energy study as a function of volume in the cubic phase of
LaMnO$_{3}$. A charge disproportionated state into planes of
Mn$^{3+}$O$_{2}$/Mn$^{4+}$O$_{2}$ was found. It is argued that the pressure
driven localisation/delocalisation transition might go smoothly through a
region of Mn$^{3+}$ and Mn$^{4+}$ coexistence.
