This section lists all Link 0 commands, which are optional
and precede the route section if present. See this page
for a more detailed discussion of the scratch file naming commands.
0 commands may be up to 500 characters in length.
Sets the amount of dynamic memory used to N words (8N bytes). The
default is 6MW. N may be optionally followed by a units designation: KB,
MB, GB, KW, MB or GW.
Locates and names the checkpoint file.
and names a single, unified Read-Write file (old-style syntax).
An alternate syntax is provided for splitting the Read-Write file
among two or more disks (or file systems). Each location is followed by a maximum
size for the file segment at that location. The default units for each size
is words; the value may be optionally followed by KB, MB, GB,
KW, MW or GW (with no intervening spaces) to indicate units.
A value of -1 for any size parameter indicates that any and all available
space may be used, and a value of 0 indicates that an existing segment
should retain its current size. The locations may be either directory locations,
or full pathnames. Note that directory specifications must include terminal
slashes (on UNIX systems).
Locates and names
the two-electron integral file(s). spec may take on either of the forms
used for the Read-Write file (described above).
Locates and names the two-electron integral derivative file(s). spec may
take on either of the forms used for the Read-Write file (described above).
Tells the program to stop the run after the Mth
occurrence of Link N. For example, %KJob L502 2 will cause
the run to terminate after Link 502 has been run for the second
time. M may be omitted; it defaults to 1.
Requests that the job use up to N processors for shared memory parallel
execution on SMP multiprocessor computers. This capability is only available on
some computer systems, and Gaussian must have been built with parallel
processing enabled. On parallel machines, the number of processors to use in production
runs is usually set in the Default.Route file, and the %NProcShared
Link 0 command is used to override this local default (e.g., to run debug jobs
on a single processor even if the default is to use 4 processors). If %NProcShared
is not used, and no default is provided in the Default.Route file, then
one processor is used.
Causes Link 0 to save scratch
files at the end of the run. By default, all non-specified scratch files are deleted
and all named scratch files are saved when the run completes successfully.
Causes Link 0 to delete scratch files at the end of a run, including any files
that were named explicitly following this directive. In other words, if
a file is named before %NoSave is encountered, it will not be saved. However,
if the % directive naming the file appears after the %NoSave directive,
the file will be retained.
For example, these commands specify a name for
the checkpoint file, and an alternate name and directory location for the read-write
file, and cause only the checkpoint file to be saved at the conclusion of the
%RWF=/chem/scratch2/water Files to be deleted go here.
%Chk=water Files to be saved go here.
If both %Save and %NoSave are specified, then the
one appearing latest in the input file takes precedence.
Tells Link 0 to take the executable (.exe file) for a link
from an alternate directory. For example %SUBST L913 /user/chem will cause
/user/chem/l913.exe to be run instead of the default executable (in $g03root).
The directory specification should be in the usual format for the machine involved.
Only the directory can be specified; the file name must have the standard form
of lnnnn.exe, where nnnn is the Link number.
Requests that the job use up to N processors for distributed memory parallel
execution. This capability is only available on some computer systems, and Gaussian must have been built with parallel processing enabled. On parallel machines, the
number of processors to use in production runs is usually set in the Default.Route file, and the %NProcLinda Link 0 command is used to override this local
default (e.g., to run debug jobs on a single processor even if the default is
to use 4 processors). If %NProcLinda is not used, and no default is provided
in the Default.Route file, then one processor is used. Note: the %NProc directive used in earlier program versions is obsolete.
This lists the TCP node name for each node to use. By default, one Linda worker is started on each node, but the optional number allows this to be varied. For example, if the job is to be run on one 4-processor SMP box machine1.myorg.edu and on one 8-processor SMP box called machine2.myorg.edu then one should specify:
This would run one Linda worker on machine1, which would run 4-way SMP parallel on that machine, and two Linda workers on machine2, each of which would run 4-way SMP parallel.
Then the job would run 6 Linda workers, 3 on machine2, and one each on machine1, machine3, and machine0.