[Pw_forum] energy for H atom

[Helen Eisenberg]

Dear All,
I want to calculate the binding energy of hydrogen to a solid slab. As a 
first stage I calculated the energy of an isolated hydrogen atom. When I 
specified the occupations, or used smearing, the calculation was fine. 
However if I didn't specify the occupations or use smearing I got the 
following error message:
     WARNING: integrated charge=     0.30000000, expected=     1.00000000

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from electrons : error #         1
      charge is wrong: smearing is needed
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      stopping ...


This happened with both a LDA and a Hartree-Fock calculation.
Why is this error occurring?
The error also occurs when I calculate the energy of the solid slab + 
hydrogen atom (the slab by itself works fine)


      WARNING: integrated charge=   256.30000000, expected=   257.00000000

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from electrons : error #         1
      charge is wrong: smearing is needed
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      stopping ...

I don't want to have to specify occupations for the slab+H atom system 
as then I'll be limited to a single k-point calculation,
Thank you for your advice,
Dr Helen Eisenberg
Fritz-Haber center for molecular dynamics,
Hebrew University of Jerusalem