The ABINIT Users Mailing List ( CLOSED )

["Zhenhua Zeng" <myid520@163.com>]

Dear Gregory,
    Thank you for your suggestions. Following you suggestions, I set nsym to 1 and get similar bond energy with you. The bond energy is 5.97ev and 6.07ev respectively using Hartwigsen-Goedecker-Hutter pseudopotential(GGA-PBE) and Fritz-Haber-Institute pseudopotential(GGA-PBE,TM scheme). 
    But I think the setting of nsym may be experiential. If there have other settings which can give a lower total energy of oxygen atom, then the bond energy of O2 will become smaller. In addition, this setting can’t work well on the calculating of bond energy of CO molecule. Thank you again.
Best regards.

> Hello !
> Two suggestions:
> 
> 1 -  Check that the ground state you find (in both cases) is
> spin-polarized with the appropriate magn.
> (Check your value of spinat!)
> 
> 2 -  the value of the bond energy depends on the result you find for the
> ground state of the free atom:
> From a general point of view with open-shell atoms, you find a lower total
> energy by using NSYM 1, which breaks the spherical symmetry (your
> supercell is a cubic box). Try this, you should have a lower total energy
> for your atomic reference, and thus a lower bond energy for the
> molecule... (tell us if it is enough)
> 
> The O2 bond energy I calculate with ABINIT is 5.95 eV, using a non
> spherical reference for the free atom (GGA-PBE, TM pseudopotentials).
> Other results with other codes in GGA-PW91 are around 6 eV. The calculated
> bondlength is always excellent (very close to 1.21 Ang).
> Good luck,
> Gregory
> 
> 


Zhenhua Zheng
Hunan University PR. China

・AOC(冠捷)六大随心技,开启"随心视"代http://design.163.com/aocmonitor/index.html

・1.5G 全国最大空间――网易126免费邮箱 http://www.126.com 火热抢注中>>>

  体验30兆超大附件发送，享受100％卡巴斯基专业杀毒……更多超G感受等您来体验！