[Pw_forum] polarizability calculation

[Olga Sedelnikova]

Dear Users,


  I'm interesting in calculation of static and dynamic electronic
polarization properties. If I understood User's Guide correctly, there are
two way: using ph.x (fpol) and vdw.x codes. Could you advice some papers
with theoretical background of these implementation?

Which is better method for nanotubes, graphite, and gpaphene?



The other problem is connected with the example34.  No modifications of
standard input files were done.

The scf calculation was ok, but effective potential calculation had
problems with stability:



     Program VdW v.4.3.2        starts on  6Dec2012 at 17:43:23



     This program is part of the open-source Quantum ESPRESSO suite

     for quantum simulation of materials; please cite

         "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);

          URL http://www.quantum-espresso.org",

     in publications or presentations arising from this work. More details
at

     http://www.quantum-espresso.org/wiki/index.php/Citing_Quantum-ESPRESSO



     Parallel version (MPI & OpenMP), running on     4 processor cores

     Number of MPI processes:               1

     Threads/MPI process:                  4



   Info: using nr1, nr2, nr3 values from input



   Info: using nr1s, nr2s, nr3s values from input

               file H.vbc.UPF: wavefunction(s)  1S renormalized



     G-vector sticks info

     --------------------

     sticks:   dense  smooth     PW     G-vecs:    dense   smooth      PW

     Sum        1369    1369    349                38401    38401    4801





     Effective Potential Calculation





          Charge difference due to FFT   0.01787941



          Charge difference due to V_eff (initial)   0.01204687



          iter #     1   charge diff.   0.82753376   thresh_veff
0.00960000



          iter #     2   charge diff.   0.13281985   thresh_veff
0.00960000



          iter #     3   charge diff.   0.84867147   thresh_veff
0.00960000



          **********unstability happens**********

          iter #     4   charge diff.   0.21607526   thresh_veff
0.00960000



          iter #     5   charge diff.   0.87173963   thresh_veff
0.00960000



........................



          **********unstability happens**********

   WARNING:     1 eigenvalues not converged

   WARNING:     1 eigenvalues not converged

   WARNING:     1 eigenvalues not converged

   WARNING:     1 eigenvalues not converged

   WARNING:     1 eigenvalues not converged

   WARNING:     1 eigenvalues not converged

          iter #    81   charge diff.   1.99492123   thresh_veff
0.00960000



          **********unstability happens**********



Thanks in advance,

-- 
Olga Sedelnikova
Nikolaev Institute of Inorganic Chemistry of SB RAS
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