On Sat, 2005-03-26 at 13:58 +0800, xywu wrote: > Dear all, > > I add a sawlike electric potential in SCF and want to get the electric > potential from pp.x. > But when i use the pp.x with plot_num=12, the electric field potential > in output file is zero.
Thank you for noticing this. You are right, there is a bug with plot_num=12. This will be fixed on the cvs version. > > But if i get the electric potential from pp.x without adding electric > field in SCF, the error occurs as follows; > > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > from punch_plot : error # -1 > e_field is not calculated > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > > what's the wrong with it. > plot_num=12 is supposed to work only if tefield=.true. in the pw.x calculation, otherwise pp.x will not plot any field and stops with an error message. > Please give me some advice. > > ! plot_num selects what is saved in filplot: > ! 0=charge > ! 1=total potential V_bare+V_H + V_xc > ! 2=local ionic potential > ! 3=local density of states at e_fermi > ! 4=local density of electronic entropy > ! 5=STM images > ! 6=spin polarization (rho(up)-rho(down)) > ! 7=|psi|^2 > ! 8=electron localization function (ELF) > ! 9=planar average of all |psi|^2 > ! 10=integrated local density of states (ILDOS) from > ! emin to emax (emin, emax in eV) > ! if emax is not specified, emax=E_fermi > ! 11=the V_bare + V_H potential > ! 12=the electric field potential > ! 13=the noncolinear magnetization. > > BTW, still another question about add_efield. > > In the file add_efield.f90 > > " !-------------------------------------------------------------------------- > subroutine add_efield(rho,vpoten,etotefield) > !-------------------------------------------------------------------------- > ! > ! This routine adds an electric field to the local potential. The > ! field is made artificially periodic by introducing a saw-tooth > ! potential. The field is parallel to a reciprocal lattice vector bg, > ! according to the index edir. > ! > ! if dipfield is false the electric field correction is added to the > ! potential given as input (the bare local potential) only > ! at the first call to this routine. In the following calls > ! the routine exit. > ! > ! if dipfield is true the dipole moment per unit surface is calculated > ! and used to cancel the electric field due to periodic boundary > ! conditions. This potential is added to the Hartree and xc potential > ! in v_of_rho. NB: in this case the electric field contribution to the > ! band energy is subtracted by deband. > " > " if (first) then > WRITE( stdout,*) > WRITE( stdout,'(5x,"Adding an external electric field")') > WRITE( stdout,'(5x,"Intensity [a.u.]: ",f15.8)') eamp > endif > if (dipfield) WRITE( stdout,'(5x,"Dipole field [a.u.]: ", f15.8)') dip > if (first) then > WRITE( stdout,'(5x,"Potential amplitude [Ry]: ", f15.8)') vamp > WRITE( stdout,'(5x,"Total length [points]: ", i5)') npoints > WRITE( stdout,'(5x,"Total length [bohr rad]: ", f15.8)') length > WRITE( stdout,'(5x,"Field is reversed between points: ",2i6)')nmax, > nmax+ndesc > endif > " > > And in a typical output file of PW.x with efield: > " > Adding an external electric field > Intensity [a.u.]: 0.01000000 > Potential amplitude [Ry]: 0.24480000 > Total length [points]: 200 > Total length [bohr rad]: 61.20000000 > Field is reversed between points: 1 161 > > " > >From the output file and the code in add_efield.f90, the "first" in the code > >is TRUE and the "dipfield" is FALSE, which means that the subroutine is > >only running only at the first call and the dipole correction in periodic > >boundary conditions is never used! Is it the truth? > > Yes this is true. However, from your output, the region where the field is reversed seems too large. This region is supposed to be a narrow region within the vacuum. > ------------------------------------------------------------ > Best regards > > Xiyong Wu(X.Y.Wu) > E_mail:xywu at imr.ac.cn > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -- Andrea Dal Corso Tel. 0039-040-3787428 SISSA, Via Beirut 2/4 Fax. 0039-040-3787528 34014 Trieste (Italy) e-mail: dalcorso at sissa.it
