The very simplest selection-expressions are single-word selectors. These selectors do not take identifiers; they are complete by themselves.
|Single Word Selector||Short Form Selector||Description|
|all||*||All atoms currently loaded into PyMOL|
|none||none||No atoms (empty selection)|
|hydro||h.||All hydrogen atoms currently loaded into PyMOL|
|hetatm||het||All atoms loaded from Protein Data Bank HETATM records|
|visible||v.||All atoms in enabled objects with at least one visible representation|
|present||pr.||All atoms with defined coordinates in the current state (used in creating movies)|
The selector none won't come up much when you are typing commands directly into PyMOL, but it is useful in programming scripts.
As the table shows, many single-word selectors have short forms to save on typing. Some short forms must be followed by a period and a space, in order to delimit the word. Short forms and long forms have the same effect, so choose the form that suits you.
PyMOL> color blue, all # It all turns blue. PyMOL> color blue, * PyMOL> hide hydro # Representations of all PyMOL> hide h. # hydrogen atoms are hidden. PyMOL> show spheres, hetatom # All the atoms defined as HETATOMS PyMOL> show spheres, het # in the PDB input file # are represented as spheres.