[Wien] cohesive energy

[Steven Homolya]

On Tue, 2 Sep 2003, Claudio de Oliveira wrote:

> Recently, I calculated the total energy for one As atom, and it is
> all right. But for one Al atom the following warning message occurs in 
> al.scf file and the total energy did not converge .
> 
> :SUM  : SUM OF EIGENVALUES =            -16.183059
> 
> :GMA  : POTENTIAL AND CHARGE CUT-OFF  14.00 Ry**.5
> :WARN : RESULT OF INTEGRATION:   8.00000; SHOULD BE:    9.00000
>         Energy to separate semicore and valencestates:  -0.53970
> 

I had the same problem. You probably need to change the method of
numerical integration from TETRA to TEMP or GAUSS when the no. of k-points
is small. For Al cohesive energy, I used GAUSS with a smoothing window 
width of 0.0002 Ry, if I remember correctly.

PS. How about us wien users putting our efforts together and start
building a database of isolated atom energies? E.g., a database of entries
consisting of E-total, Z, RMT, GAUSS/TEMP broadening, unit cell size,
convergence criteria.

Steve

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