Input File Structure

Input File Structure#

In Penguin, the molecule and input specifications are contained in a single file, the INPUT.inp.
This file is organized into sections, each starting with “@sectionname” and ending with “@end”.
The sections and their content can be arranged in any order.

@method settings  
keyword: value  
keyword: value  
...  
keyword: value  
@end  

@memory  
keyword: value  
keyword: value  
...  
keyword: value  
@end  

@jobs  
keyword: value  
keyword: value  
...  
keyword: value  
@end  

@scf  
keyword: value  
keyword: value  
...  
keyword: value  
@end  

@molecule  
keyword: value
keyword: value
...
keyword: value
@end

Example @molecule Section#

An example of the @molecule section in the INPUT.inp file demonstrates how to define the molecular structure and related parameters such as charge, multiplicity, and units of the coordinates.
The following is such an example:

@molecule  
charge: 0  
multiplicity: 1  
units: bohr  
xyz:  
O 0.0000000000 0.0000000000 0.0000000000  
H 0.0000000000 1.4304281903 1.1071565216  
H 0.0000000000 -1.4304281903 1.1071565216  
@end

In this example:

  • charge specifies the net charge of the molecule (0 in this case, indicating a neutral molecule).

  • multiplicity defines the spin multiplicity of the molecule (1 indicates a singlet state).

  • units sets the unit of measurement for atomic coordinates (here the distances are provided in Bohr).

  • xyz lists the atomic coordinates, with each line containing the element symbol followed by its x, y, and z coordinates.

This configuration describes a water molecule (H\(_2\)O) with the oxygen atom at the origin and the two hydrogen atoms positioned symmetrically.

Required Sections#

Currently, three sections are strictly required to perform a Penguin calculation:
@method settings
@jobs
@molecule

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