Total energy estimation for Pd/Al bimetallic surfaces by a parallel computation scheme

A numerical calculation scheme for the multicenter problem in large molecul es and clusters is presented by applying the message-passing inter-face (MP I) in a massively parallel computer that uses the density functional method . The multicenter problem associated with the Coulomb singularity of an ato m is efficiently treated by the parallel processors by allocating several a toms into each processor element (PE). The order N-2/P tuning is obtained f or the Coulomb energy calculation by using the MPI which transfers Coulomb potential field between PE's. This method is applied to estimate the total energy of the reconstructed Al/Pd bimetallic surface. The energy estimation by the charge density of a superposition of isolated atomic charge fragmen ts predict a stabilization caused by the reconstruction, being consistent w ith a self-consistent-field (SCF) cluster calculation of the bimetallic sur face.