This example is a test case of 5-azauracil. The starting configuration
is taken from a previous run using an nst ensemble. The input to the
nst run was a 4x2x3 supercell of the experimental structure, which has
8 molecules per cell and 11 atoms per molecule. The molecules are not
exactly planar in the experimental structure. This is reflected in the
description of the distributed multipoles in the FIELD file where the
molecules form two sets of enantiomers with small non-zero odd-z
components. The OUTPUT from the test case was run on 4 nodes of the
SP2 at Daresbury. The precision for the Ewald sums is 1.0E-04 for
direct space monopole-monopole interactions, 1.0E-07 for direct space
higher multipoles and 1.0E-04 for reciprocal space. In this case the
DL_MULTI cutoff algorithm in direct space finds that total pole order
= 1 needs the largest cutoff to obtain the desired accuracy. The kmax
values in reciprocal space drop off rapidly with increasing total
multipole order and for l
1 no terms are needed. For this setup 2.7 s
per time step was required. Most of the time was spent doing the
direct space sums, because of the small reciprocal space precision.