We analyze the effect of the pressure variations on the electron and the positron distributions in the boron phosphide. On the basis of the pseudopotential band structure calculations (EPM) and the independent particle approximation (IPM), the electron and the positron wave functions are derived, respectively. The resulting wave functions are used to compute the corresponding charge densities along the <111> axis. The integrated electron-positron momentum densities, for different pressures, are calculated along the (001) and (110) directions. The results are used to analyze the evolution of the bonding properties and to predict how pressure could affect positron annihilation results in the boron phosphide.
