# set_mass

Set the atomic mass for a specific atom. This command can appear in the global context.

### Options

atom

Specify an atom index whose mass is to be altered. Note that indexing starts at 1.

This option is mandatory.

• The type is int
• There is no default value.
• The value must be greater than or equal to 1.0
mass

Specify a mass.

This option is mandatory.

• The type is quantity
• There is no default value.