The unit-system section¶

The unit-system section is used in combination with the units keyword from the system section for defining custom system of units. When defining a custom unit system, the units keyword is used to select the new system and the unit-system section is defining the base units.

Example unit-system section:

[system]
units = "new-system"

[unit-system]
name = "new-system"
length = [
    1.0,
    "bohr",
]
mass = [
    9.81e-31,
    "kg",
]
energy = [
    1.0,
    "kcal/mol",
]
charge = "e"

Note that the unit-system section is optional.

Keywords for the unit-system section¶

For the unit-system section the scale for each dimension is specified using the keywords:

Table 44 Keywords for the unit-system section¶
Keyword	Description
length	Specify the scale and base unit for the length dimension.
mass	Specify the scale and base unit for the mass dimension.
energy	Specify the scale and base unit for the energy dimension.
charge	Specify the base unit for the charge dimension

Keyword length¶

length = tuple like (float, string)

The length keyword specifies the scale and base unit for the length dimension. This is done on the form:

[unit-system]
length = [1.0, "baseunit"]  # [scale, base unit]

For an overview of the possible base units, please see the description in the manual section describing units in PyRETIS. Also, note that the 'baseunit' string is case-sensitive!

Default: None. This keyword must be specified if the unit-system section is used.

Keyword mass¶

mass = tuple like (float, string)

The mass keyword specifies the scale and base unit for the mass dimension. This is done on the form:

[unit-system]
mass = [1.0, "baseunit"]  # [scale, base unit]

For an overview of the possible base units, please see the description in the manual section describing units in PyRETIS. Also, note that the 'baseunit' string is case-sensitive!

Default: None. This keyword must be specified if the unit-system section is used.

Keyword energy¶

energy = tuple like (float, string)

The energy keyword specifies the scale and base unit for the energy dimension. This is done on the form:

[unit-system]
energy = [1.0, "baseunit"]  # [scale, base unit]

For an overview of the possible base units, please see the description in the manual section describing units in PyRETIS. Also, note that the 'baseunit' string is case-sensitive!

Default: None. This keyword must be specified if the unit-system section is used.

Keyword charge¶

charge = string

The charge keyword specifies base unit for the charge dimension. This is done on the form:

[unit-system]
charge = "baseunit"

For an overview of the possible base units, please see the description in the manual section describing units in PyRETIS. Also, note that the 'baseunit' string is case-sensitive!

Default: None. This keyword must be specified if the unit-system section is used.