The General Panel

The General panel allows you to select commonly used general calculation options. It is illustrated below:


Gaussian Calculation Setup General Options Panel

This panel contains a set of commonly used options. The following table indicates the Gaussian keywords corresponding to the checkboxes:

Option Default Keyword
Use Quadratically Convergent SCF Off SCF=QC
Use Modified Redundant Coordinates On Geom=ModRedundant
Ignore Symmetry Off NoSymm
Use Counterpoise Off Counterpoise
Write Cartesians On Cartesian coordinates are written (Off=Z-matrix coordinates)
Additional Print Off #P
Write Connectivity On Geom=Connectivity
Write PDB Data On ResNum, ResName, PDBName (in molecule specification)
Write Gaussian Fragment Data On Fragment (in molecule specification)
Use MaxDisk Off MaxDisk=values
Compute polarizabilities Off Polar
Compute optical rotations Off Polar=OptRot
Read Incident Light Freqs No CPHF=RdFreq

The Use Modified Redundant Coordinates item is enabled only if you have created redundant coordinates with the Redundant Coordinate Editor. If not, the item is ignored (despite its default value). Write Gaussian Fragment Data and Write PDB Data are enabled by default, but have no effect unless the corresponding items are defined.

The Write Connectivity option also includes the appropriate additional input section(s) in the Gaussian input file.

If Write Cartesians is unchecked, then a Z-matrix will be written to the input file instead of Cartesian coordinates.

Note: Consult the discussion of the SCF keyword in the Gaussian User’s Reference for recommendations for unusual/problem cases (SCF=QC is not always the best next choice).

Retrieving Items from a Checkpoint File

The items in the Read Data From Checkpoint File section control which items are retrieved from the checkpoint file from a previous job:

Option Default Keyword
Geometry No Molecule Specification: Geom=Check
Title, Charge and ... Molecule Specification: Geom=AllCheck
Optimization Force Constants No Read Internal: Opt=ReadFC
Read Cartesian: Opt=RCFC
MO Guess Off Guess=Read

See here for a list of equivalent G16 Keywords for Gaussian Calc. Setup selections.