- Options
- Equivalencies
Command Line Options
The g16 command accepts the following options on all platforms:
| Option | Description | Example |
| -r=list | Route section default keyword list | -r="Int=SuperFine Freq=HPModes" |
| -m=value | Memory amount for Gaussian jobs | -m=200GB |
| -c=list | Processor/core list for multiprocessor parallel jobs | -c="0-31" |
| -g=list | GPUs=Cores list for GPU parallel jobs | -g="0-8=0-6,31,32" |
| -s=command | Command to use for starting workers for network parallel jobs: generally ssh or rsh, but any command may be specified. | -s=ssh |
| -w=list | List of hostnames for network parallel jobs. | -w="apple,banana,cherry" |
| -p | Number of processors/cores for multiprocessor parallel jobs. Deprecated; use -c. | |
| -l | Number of nodes for network parallel jobs. Deprecated; use -w. | |
| -x | Complete route for the job (the route is not read from the input file). | -x="# b3lyp/6-31G(d) opt freq" |
| -y | Checkpoint file. | -y="$HOME/project3/gfp.chk" |
| -fchk | Generate the specified formatted checkpoint file as well as a binary one, and update it each time the checkpoint file is updated. | -fchk=/plots/job8.fchk |
| -z | Read-write file. | -z=/scratch2/fox7.rwf |
| -ic | Existing checkpoint file from which to read input. | -ic=job6 |
| -im | Matrix element file from which to read input. | -im=fox7.dat |
| -im4 | Matrix element file using 4-byte integers from which to read input. | -im4=fox12 |
| -im8 | Matrix element file using 8-byte integers from which to read input. | -im8=fox7 |
| -ir | Raw matrix element file from which to read input. | -ir=job6 |
| -ir4 | Raw matrix element file using 4-byte integers from which to read input. | -ir4=job27 |
| -ir8 | Raw matrix element file using 8-byte integers from which to read input. | -ir8=job7 |
| -oc | Output checkpoint file. Generally redundant with -y. | |
| -om | Output matrix element file. | -om=job16new_mat |
| -om4 | Output matrix element file using 4-byte integers. | -om4=job32mat |
| -om8 | Output matrix element file using 8-byte integers. | -om8=job64mat |
| -or | Output raw matrix element file. | -or=job7_raw |
| -or4 | Output raw matrix element file using 4-byte integers. | -or4=proteins_rawdat |
| -or8 | Output raw matrix element file using 8-byte integers. | -or8=proteins_rawdat |
Note that the quotation marks are often required around option values to avoid modification by the shell.
Most options that control how Gaussian 16 operates can be specified in any of 4 ways. From highest to lowest precedence these are:
- As Link 0 input (%-lines): This is the usual method to control a specific job and the only way to control a specific step within a multi-step input file. Example: %CPU=1,2,3,4. For full documentation on Link 0 command, see Link 0 Commands
- As options on the command line: Command line options are useful when you want to define aliases or other shortcuts for different common ways of running the program. Example: g16 -c="1,2,3,4" …
- As environment variables: This is most useful in standard scripts, for example for generating and submitting jobs to batch queuing systems. Example: export GAUSS_CDEF="1,2,3,4"
- As directives in the Default.Route file: This is most useful when one wants to change the program defaults for all jobs. Example: -C- 1,2,3,4
When searching for a Default.Route file the current default directory is checked first, followed by the directories in the path for Gaussian 16 executables: environment variable GAUSS_EXEDIR, which normally points to $g16root/g16.
The following table lists the equivalences among Link 0 commands, command line options, Default.Route items and environment variables. The -h, -o options and the -i and -o option classes were introduced in [REV B], as were their corresponding environment variables.
| Default.Route | Link 0 | Option | Env. Var. | Description |
| Gaussian 16 execution defaults | ||||
| -R- | -r | GAUSS_RDEF | Route section keyword list. | |
| -M- | %Mem | -m | GAUSS_MDEF | Memory amount for Gaussian jobs. |
| -C- | %CPU | -c | GAUSS_CDEF | Processor/core list for multiprocessor parallel jobs. |
| -G- | %GPUCPU | -g | GAUSS_GDEF | GPUs=Cores list for GPU parallel jobs. |
| -S- | %SSH=command | -s | GAUSS_SDEF | Program to start workers for network parallel jobs. %UseSSH is equivalent to %SSH=ssh and %UseRSH similarly specifies rsh. |
| -W- | %LindaWorkers | -w | GAUSS_WDEF | List of hostnames for network parallel jobs. |
| -P- | %NProcShared | -p | GAUSS_PDEF | #processors/cores for multiprocessor parallel jobs. Deprecated; use -C-. |
| -L- | %NProcLinda | -l | GAUSS_LDEF | #nodes for network parallel jobs. Deprecated; use -W-. |
| Archive entry data | ||||
| -H- | -h | GAUSS_HDEF | Computer hostname. | |
| -O- | -o | GAUSS_ODEF | Organization (site) name. | |
| Utility program defaults | ||||
| -F- | GAUSS_FDEF | Options for the formchk utility. | ||
| -U- | GAUSS_UDEF | Memory amount for utilities. | ||
| Parameters for scripts and external programs | ||||
| # section | -x | GAUSS_XDEF | Complete route for the job (route not read from input file). | |
| %Chk | -y | GAUSS_YDEF | Checkpoint file for job. | |
| %RWF | -z | GAUSS_ZDEF | Read-write file for job. | |
| %OldChk | -ic | GAUSS_ICDEF | Existing checkpoint file from which to read input. | |
| %OldMatrix | -im | GAUSS_IMDEF | Matrix element file from which to read input. | |
| %OldMatrix=(file,i4lab) | -im4 | GAUSS_IM4DEF | Matrix element file using 4-byte integers from which to read input. | |
| %OldMatrix=(file,i8lab) | -im8 | GAUSS_IM8DEF | Matrix element file using 8-byte integers from which to read input. | |
| %OldRaw | -ir | GAUSS_IRDEF | Raw matrix element file from which to read input. | |
| %OldRaw=(file,i4lab) | -ir4 | GAUSS_IR4DEF | Raw matrix element file using 4-byte integers from which to read input. | |
| %OldRaw=(file,i8lab) | -ir8 | GAUSS_IR8DEF | Raw matrix element file using 8-byte integers from which to read input. | |
| -oc | GAUSS_OCDEF | Output checkpoint file. Generally redundant with -y/GAUSS_YDEF. | ||
| -om | GAUSS_OMDEF | Output matrix element file. | ||
| -om4 | GAUSS_OM4DEF | Output matrix element file using 4-byte integers. | ||
| -om8 | GAUSS_OM8DEF | Output matrix element file using 8-byte integers. | ||
| -or | GAUSS_ORDEF | Output raw matrix element file. | ||
| -or4 | GAUSS_OR4DEF | Output raw matrix element file using 4-byte integers. | ||
| -or8 | GAUSS_OR8DEF | Output raw matrix element file using 8-byte integers. | ||
Note that the quotation marks are normally required around the specified value for the command line and environment variables to avoid modification of the parameter string by the shell.
Last updated on: 23 July 2019. [G16 Rev. C.01]
