phase
When 
phase is 
yes (the default), the orbital
is represented with two colors, to distinguish places where the wave
function is positive and negative. When 
phase is 
no,
the whole orbital is represented with just one color.
Example: <orbital ... phase="yes"/> (default)
Allowed values: yes, no (optional)
frame
When 
frame is 
yes (the default), a cubic frame
is shown around the orbital, with a edge length equal to twice the
sampling radius. When 
frame is 
no, no frame is shown.
Example: <orbital ... frame="yes"/> (default)
Allowed values: yes, no (optional)
octants
Each orbital is divided in 8 octants, that can be made visible or not,
according to a sequence of 8 bits. The 8 octants are ordered from
-x-y-z to +x+y+z, where x moves faster and z moves slower, so the
first 4 bits (counting from the left) are for the 4 octants with
-z coordinate (below) and among these the first 2 bits are for
the 2 octants with -y coordinate (below). To set which octants
should be shown or hidden, set the corresponding bits to 1 or 0.
By default all octants are shown.
Example: <orbital ... octants="11111111"/> (default)
Allowed values: all 8 bit sequences (optional)
axes
When 
axes is set to 
radius, axes are shown with the radius
length (when 
frame is disabled) or the diameter length (when
frame is enabled). When 
axes is set to 
unit, axes
are shown with a unit length. When 
axes is set to 
bohr,
axes are shown with the length of Bohr first radius. When 
axes is
set to 
none, no axes are shown (the default). The options 
bohr
and 
unit are useful only for small orbitals, otherwise the axes are
barely visible.
When 
frame is enabled (the default), axes are positioned along
the frame edges, starting from the xyz lower corner. When 
frame
is disabled, axes start from the orbital center. 
Example: <orbital ... axes="none"/> (default)
Allowed values: radius, bohr, unit, none (optional)