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| Operands | none |
POTE
atomic assignments
short range potential definitions
ENDS
This directive instructs the program to call the short range potential
input routine. This routine is menu-driven with a menu of sub-directives.
The sub-directives fall into seven classes: species data, short range
interactions, core-shell interactions, three-body interactions, torsion
interactions, restart sub-directives and subroutine termination. Restarts
are only relevant for DMAREL. All of these classes, except the restart,
are described below.
Table:
Directives for the potential input subroutine
|
Directive
class
|
Directives |
| SPEC, ENDS | |
|
BUCK, MODI, LENN, MORS, BUC4, SPLI, MORQ, SPRI, COUL, VDWA, HULB, BUC7, NONE, BSPL, DBUC, BVCK, DBVC |
|
| HARM | |
| TOHA | |
| RELB, ENDS, LCON, RETH |
The directive order depends on whether this is an initial
call to the potential input routine or a restart. If it is a restart,
the only three permitted directives after
POTE are RELB,
RETH and ENDS.
If it is an initial call, the directives RELB
and RETH are not permitted.
The directive LCON
must be supplied in the initial call if restarts will follow in which
a different substance is being considered, as all the potential information
for all substances is read in during the first call. The directive
order for the initial call must be:
| Directives | Comments |
| SPEC | Followed by subdirectives (See below) |
| LCON | Optional (Only needed if more than one substance) |
| Others | May be given in any order |
| ENDS |
The limits on the numbers of potentials etc. are determined by a number of PARAMETER statements in the FORTRAN. These limits may be reset simply by changing every occurence of the PARAMETER statement to the new limit. The variable names and default limits are given in the following table.
Table:
Potential Parameters Limits
| Variable | Default | Meaning |
| Value | ||
| MAXPOT | 100 | Maximum permitted number of potentials |
| MAXRNG | 40 | Maximum number of ranges for each potential |
| MAXTHB | 50 | Maximum number of types of three-body bond |
| MAXHRM | 20 | Maximum number of HARM directives permitted |
| MAXTYP | 20 | Maximum number of species (Cores + Shells) permitted |
| MAXTOR | 50 | Maximum number of types of torsions |
Note that these limits do not necessarily apply to all
versions of the programs on all machines, in particular DMAREL has MAXPOT
set to 100 in most versions rather than 40.
Printed output and
error messages from this section of the program are given below. Printed
output may be supressed using the option
PRIN POTE 0 in the default parameter changes.
Printed output
START OF SHORT RANGE POTENTIAL PROCESSING
This is always output
by the program.
Error messages
ERROR - INVALID DIRECTIVE GIVEN IN ABOVE LINE
The line above began with an invalid directive.
ERROR - THIS DIRECTIVE IS ONLY PERMITTED FOR THE FIRST CALL OF POTE
The job is being restarted after the first defect calculation and an invalid directive has been found.
ERROR - THIS DIRECTIVE IS NOT PERMITTED FOR THE FIRST CALL OF POTE
The directives RELB and RETH are only permitted in a restart.
ERROR - LCON MUST BE GIVEN AFTER SPECIES INPUT
If LCON is used, it must only be used after the species input.
ERROR - SPECIES MUST BE READ IN BEFORE POTENTIALS
The program has read in a valid potential input directive, but the species have not yet been read in using SPEC.
ERROR - ABOVE LINE CONTAINS A SPEC DIRECTIVE - ONLY ONE IS PERMITTED
Only one SPEC directive is permitted.
ERROR - IF RELB DIRECTIVE IS USED IT MUST BE THE FIRST DIRECTIVE
ERROR - IF RETH DIRECTIVE IS USED IT MUST BE THE FIRST DIRECTIVE
These two error messages
are produced if a restart is attempted and the directives are out of order.
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