Methods of a Structure object¶
Properties vs Methods¶
In addition to properties, an object can also have methods. Typically, a method will perform a calculation; it may also save the results of that calculation. For example, you might want to convert a conventional unit cell into a primitive unit cell. You can do this with nacl_structure.get_primitive_structure(). Try this in your python console:
nacl_structure.get_primitive_structure()
You'll see it prints out a new structure. We had the primitive structure already, so it should be identical to our output from before.
Save the output to a new variable¶
For this method, we save it as a new Structure object by assigning it to the name nacl_prim:
nacl_prim = nacl_structure.get_primitive_structure()
nacl_prim.density
Giving parameters to methods¶
Note that all methods end with parentheses (). This allows us to alter the method. For example, get_primitive_structure() makes use of symmetry in its calculation, so if we do:
nacl_structure.get_primitive_structure(tolerance=0.1)
The calculation will allow atoms that are nearly in their 'symmetrically correct' positions (within 0.1 Å) to be identiified as symmetrical. Note, we didn't have to set a tolerance before because there are default values being used. Some methods don't have defaults. For example, the make_supercell method require you to specify a supercell size.
There are many other methods available for structures too:
nacl_structure.add_oxidation_state_by_guess()
nacl_structure.make_supercell([2,2,2])
Exploring other methods and properties¶
To get a quick look at all of the properties and methods available, type nacl_structure into the terminal but don't hit enter yet. Then add a period so you have nacl_structure., and finally, hit tab. You should see a list pop up with everything available.
Select lattice, then do this tab trick again. The list should look similar to this (this image isn't for a structure object though):
This can be done with any class or any object. There are many different classes in Simmate, but you'll interact with Structure the most. To fully understand all of the options for these classes, you'll need to explore the code's documentation, which we will cover in the next guide.