Vectorization of molecular dynamics Fortran programs using the cyber 205 vector processing computer

A concept of vectorization of molecular dynamics Fortran programs for the use of the Cyber 205 machine is presented. It is shown that for calculations with larger particle systems the program runs faster on the 205 than on the Cray-1 by about a factor of two. Against conventional computers like the Cyber 175 an acceleration by a factor 10–15 is expected. A bit control vector is used instead of a neighbour list, which in principal provides calculations up to 6912 particles for the memory capacity of the Cyber 205. However, because the application of the bit vector requires computation times which grow proportional to N2, the CPU time for particle numbers of more than 2048 becomes prohibitively large.