[Pw_forum] Cohesive Energy of N2 molecule

[Izaak Williamson]

Dear all,

I am trying to calculate the cohesive energy of the N2 molecule using the 
attached input file (relax.in) and am getting a value of -16.57 eV. I use DFT 
with GGA and the pseudo-potential N.pbe-rrkjus.UPF. Other work [Fuchs et. al., 
Phys. Rev. B 65, (2002)245212] has performed similar calculations and obtained 
values ~10.5 eV. They even list an experimental value of 9.76 eV. Why is my 
value so much higher? Is there anything in my input file that could be giving 
inaccurate results? Is it my pseudo-potential that is causing this problem?

Thanks for any help.

-- 
Izaak Williamson
Research Assistant
Physics Department
Boise State University
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20110503/9e728584/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: relax.in
Type: application/octet-stream
Size: 663 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20110503/9e728584/attachment.obj>