The ABINIT Users Mailing List ( CLOSED )

[Steven Homolya <Steven.Homolya@spme.monash.edu.au>]

On Tue, 25 Nov 2003 01:29 am, zeng zhenhua wrote:
> Dear ABINIT users:
> I have been read the tutorial of abinit several times, but I have some
> questions about tutorial 1 and 2. firstly, In tutorial 2,acell is given
> through the convergence on the interatomic distance and atomisation energy.
> But I think this acell is very rough.. I want to known how to get accurate
> acell of hydrogen. Note, I find the “optcell” can’t be used to
> automaticly optimize the acell of hydrogen . Secondly, although we known
> the structure of hydrogen is hcp, it is treated as sc in tutorial 1 and 2 .
> I want to known how to judge which structure it is, it is hcp, sc or some
> structure else. Do you have any suggestion for these problems? Thanks in
> advance.
> Zhenhua Zeng
>

As stated in their titles, the tutorials are about the hydrogen (H_2) 
_molecule_, not about the solid form you mention, which occurs only at 
extremely high pressures! It should be evident what acell means in this 
context, why it needs to be fairly large, and why it's not "optimised".

-- 
Steven Homolya
School of Physics and Materials Engineering
Monash University VIC 3800
Australia
Tel: INT +61 3 9905 3694
Fax: INT +61 3 9905 3637