Units Keywords in the Jaguar Input File

The keywords iunit, eunit, and espunit set units for geometry, energy, and electrostatic potential units. The iunit keyword, whose default value is 1, describes what units the geometry is assumed to have, as indicated in Table 1. It also sets the length units for plot grids and for the location of point charges. The eunit keyword sets the energy units for thermochemical properties and for harmonic potentials used for harmonic constraints. The espunit keyword sets the units for output of electrostatic potentials.

Table 1. Options for the units keywords

Keyword

Value

Description

iunit

0

Geometry units are bohr and radians

 

1

Geometry units are angstroms and degrees

 

2

Geometry units are bohr and degrees

 

3

Geometry units are angstroms and radians

eunit

1

Energy units are kcal/mol

 

2

Energy units are kJ/mol

espunit

1

Electrostatic potential in units of kcal mol−1 electron−1. (Useful for comparing molecules)

 

2

Electrostatic potential in units of kT electron−1 at 298.15 K. (Useful for comparing molecules)

 

3

Electrostatic potential in atomic units.

 

4

Electrostatic potential in units of kcal mol−1.

 

5

Electrostatic potential in units of kT mol−1 at 298.15 K.

 

6

Electrostatic potential in units of electron volts (eV).