[Pw_forum] Cohesive Energy of N2 molecule

[elbuesta at icqmail.com]

 Dear Izaak Williamson,

I believe the most important thing to be included is the magnetisation for the isolated N atom, something I am not sure if you included it or not. Attached you will find your input slightly changed for the N2 molecule and the N atom. The cohesive energy obtained with this input was 10eV. I hope it helps!

 


 Fabio Negreiros
IPCF - CNR
Pisa, Italy

 

-----Original Message-----
From: Izaak Williamson <izaakw89 at yahoo.com>
To: pw_forum at pwscf.org
Sent: Tue, May 3, 2011 6:54 pm
Subject: [Pw_forum] Cohesive Energy of N2 molecule



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



 
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