[Pw_forum] CO and N2 Crystals

[Amos Leffler]

Dear Forum,
          I would like to calculate the properties of the CO and N2 
structures.  Example03 calculates the scf for CO but does nothing about 
the crystal.  The problem is whether to use ibrav=0 to place each atom 
or to use CO units with ibrav=2.  Little is said in the Users Guide 
about either of these approaches and I have looked at some of Forum 
records but haven't found anything about either of these methods.  
Hopefully someone can point me to references or suggestions.  There 
appears to be nothing about using polyatom elements for crystalline 
structure but this would be a very useful ability since there are many 
cases where it could be applied.
                                                                         
                     Amos Leffler