Gaussian software lables
In the latter case, the Hessian is given in lower triangular form: α ij, i=1 to N, j=1 to i. The second section is present only if first derivatives or frequencies were requested, and the final section is present only if frequencies were requested. The output file is in fixed format, and has the following data (all in atomic units): Items The remaining lines specify the atomic number, coordinates and molecular mechanics charge for each atom. The first line specifies the number of atoms in the molecule, what derivatives are to be computed ( 0=energy only, 1=first derivatives, 2=second derivatives), and the molecule’s charge and spin multiplicity. The input file has the following format: #atoms derivatives-requested charge spin atomic# x y z MM-charge MM-atom_type Repeated for each atom. The specified script is always passed the parameters mentioned above as its final six arguments. $ RunTink Amber layer InputFile OutputFile MsgFile FChkFile MatElFile In this example, the actual command would be: The structured is documented in a separate section following the examples.Īll of these files are deleted by Gaussian once the results have been recovered.Īdditional arguments to the script may also be included: This is a simple Fortran unformated file designed to export data such as the overlap and Core Hamiltonian matrix and two-electron integrals in an extensible format.
#GAUSSIAN SOFTWARE LABLES PLUS#
The output formatted checkpoint file can contain an initial two blank lines plus the data to be updated in the usual format it does not need to contain any information which is to remain unchanged. If the appropriate options are set to link 402, then this file is created from the read-write file before starting the external script, and may be read to import results after the script finishes instead of Gaussian input being provided via OutputFile.
The name of a file for messages if the script creates this file, then its contents are copied to the Gaussian output file.Ī formatted checkpoint file. The name of the file which should be read in after the external program completes. The name of the file Gaussian has prepared as input for the external program.
$ Gau_External layer InputFile OutputFile MsgFile FChkFile MatElFileĪ key letter indicating whether the computation is being performed on the real system ( R), the model system of a 2-layer ONIOM or the middle layer of a 3-layer ONIOM ( M), or the model system of a 3-layer ONIOM ( S).
SCRIPT INVOCATIONīy default, the Gau_External script is passed six parameters: You may specify a different script by including its name as the option to the External keyword: e.g., External=MyScript. The converted file for use by Gaussian is referred to as the “output file.” This script, which is provided by the user, is expected to:Ĭonvert the text file-referred to as the “input file”-into input for another program.Ĭonvert the results into a standard text form for recovery by Gaussian. A text file is produced with the current structure, and a script named Gau_External is run by default (see below for information on specifying an alternate script). Gaussian uses a standardized interface to run an external program to produce an energy (and optionally a dipole moment or forces) at each geometry. This mechanism is primarily intended to facilitate the use of external programs to provide the low-level calculations in ONIOM calculations, but can also be used to conduct geometry optimizations using Gaussian’s optimizer with external programs providing the function values and derivatives. Requests a calculation using an external program. G09 Keyword: External External DESCRIPTION