input format 1

asymmetric_unit_cell headline - file type specifier
[cell] 4.9134 4.9134 5.4053 90 90 120 cell parameters: a b c [Angstrom] alpha beta gamma [deg]
[natom] 2 number of atoms
[nbond] 1 0.2 number of bonds (the second value eg:"0.2" is optional and means the allowed margin of the bondlengths)
[npoly] 0 number of polyhedra
[space_group] 154 1 space group number & setting
[title] Si-O2 (quartz) title for screen and printing
[atoms] start mark for atom data section
SI 14 0.5 0.5 0

O 8 0.4141 0.2681 0.7855

atom_label atomic_number x y z (shell number)

In the sixth column an extra number can be specified. I called it shell number, since I use it to switch on/off different shells in a big cluster by using [VIEW] [SHELL SLECTOR] (see example file cluster.jsv)

[bonds] start mark for bond pairs
1 2 atom1 atom2 . .
[poly] start mark for polyhedra specification (vertex atoms)
[origin] new! (optional)
0.5 0.5 0 origin shift for cell box only

You may leave empty lines between the [..]-entries!