c CCLRC
Section 5.2
cutpot
real
cutoff used to define tables °
A
ngrid
integer
number of grid points in tables
The subsequent records define each tabulated potential in turn, in the order indicated by the
specification in the FIELD file. Each potential is defined by a header record and a set of data
records with the potential and force tables.
header record:
atom 1
a8
first atom type
atom 2
a8
second atom type
potential data records: (number of data records = Int((ngrid+3)/4))
data 1
real
data item 1
data 2
real
data item 2
data 3
real
data item 3
data 4
real
data item 4
force data records: (number of data records = Int((ngrid+3)/4))
data 1
real
data item 1
data 2
real
data item 2
data 3
real
data item 3
data 4
real
data item 4
5.1.6.3
Further Comments
It should be noted that the number of grid points in the TABLE file should not be less than the
number of grid points DL POLY 3 is expecting. (This number is given by the parameter mxgrid
calculated in the setup module file - see Section
and
.) DL POLY 3 will re-interpolate
the tables if ngrid>mxgrid, but will abort if ngrid<mxgrid.
The potential and force tables are used to fill the internal arrays vvv and ggg respectively (see
Section
). The contents of force arrays are derived from the potential via the formula:
G(r) = -r
r
U (r) .
(5.6)
Note this is not the same as the true force.
5.2
The OUTPUT Files
DL POLY 3 produces up to eight output files: HISTORY, DEFECTS, OUTPUT, REVCON, RE-
VIVE, RDFDAT, ZDNDAT and STATIS. These respectively contain: an incremental dump file of
all atomic coordinates, velocities and forces; an incremental dump file of atomic coordinates of de-
fected particles (interstitials) and sites (vacancies); an incremental summary file of the simulation;
a restart (final) configuration file; a restart (final) statistics accumulators file; a radial distribution
data file; Z-density data file and a statistical history file.
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