[QE-users] The orbitals of a hydrogen atom

[Kazume NISHIDATE]

Dear Higuchi,

> However, the orbitals obtained with Quantum-Espresso (assuming the ILDOS
> pattern as the orbital) were all spherically symmetric orbitals

>                         nat = 1,
>                        ntyp = 1,

You are considering only one atom in the orthorhombic cell. 
In this case, the orbitals px, py, and pz cannot be separated unambiguously 
since the atom cannot distinguish the x, y, or z-axis. 
In other words, there is no way for the hydrogen to determine the 
particular axis. Hydrogen is in an ‘approximated’ vacuum.
Hence, these orbitals are energetically degenerated.


>                     ecutwfc = 26 ,
>                     ecutrho = 156 ,
>                        nbnd = 228,

I can't imagine the necessity of considering the 228 bands for only one 
hydrogen in a supercell. Is it an educational purpose?
If so, visualizing the analytically delivered orbital functions should 
be sufficient.

Here are some other notes;

The cutoff energy needs to be higher for your purpose. 
The number 'nbnd=228' is almost nonsense.

I’m not sure, but Wannier90 would be able to plot 'molecular orbital'
like crystal orbital. But there will be similar restrictions. 

Or you can try to use the Gaussian or Hondo to produce your higher 
order orbitals. In these cases, you will be required to specify these 
particular axes.



西館数芽
Kazume NISHIDATE Ph.D

Department of Systems Innovation Engineering,
Graduate School of Science and Engineering, Iwate University
4-3-5 Ueda, Morioka, Iwate, 020-8551 JAPAN
Phone:+81-19-621-6391
kazume.nishidate at gmail.com, nisidate at iwate-u.ac.jp
https://sites.google.com/site/nisidatelab/