tal structure must also be specified 
in terms of the offset from the origin. One can specify different offsets, or 
boundary locations, for each atom (set of symmetry equivalent atoms) in case 
the slice is not considered to be strictly planar - see section V-2. If you 
choose to use individual offsets for each atom, you will be prompted for the 
offsets during atom input - the offset entered in this section will be used 
only for display of boundary edges of the slice. 

Atoms lying exactly on the "upper" boundary - (the face to which the slice is 
defined to be parallel) are excluded from the slice, whereas atoms lying 
exactly on the "lower" boundary (the face with indices negative to the "upper" 
face) are included. 

[B.3.3.4] NO BOUNDARIES (MOLECULE). 

No boundaries whatever are used if this option is chosen, nor are any 
translations applied. That is, the atoms in the molecule are just the input 
atoms and all of those generated by the point-group symmetry specified in 
[B.3.2] (or the input atoms, if there is no symmetry). 

[B.3.3.5] TRANSLATION LIMITS (POLYMER). 

In this option, the contents of the central unit cell plus others within 
specified limits are accepted.  The central or zero unit cell contains atoms 
with fractional coordinates zero (inclusive) to one (exclusive).  The lower 
limit to unit-cell translations is normally zero or negative and the upper 
limit is normally zero or positive.  Disabling the translation entirely for an 
axis is equivalent to setting the limits at zero.  The translations belong to 
the Bravais lattice, not the primitive lattice. 

As an example of application to a crystal, putting the lower limit at -2 and 
the upper limit at +1 for all axe