<DIV>Dear all</DIV>
<DIV>   When I add external electric field to optimize the structure .It runs very very slower than not add the electric field , after 2 days ,the output file is still as following :</DIV>
<DIV> </DIV>
<DIV> iteration #  1     ecut=    30.00 Ry     beta=0.20<BR>     Davidson diagonalization with overlap<BR>     ethr =  1.00E-02,  avg # of iterations =  4.4<BR> PAY ATTENTION: EL FIELD AND OCCUPATIONS</DIV>
<DIV>     Expectation value of exp(iGx):<BR> (2.751012649613009E-016,-3.679346535033460E-017)  0.866025403784439<BR>     Electronic Dipole per cell (a.u.) -0.482785724081663<BR>     Ionic Dipole per cell (a.u.)   3794.73195575151<BR> PAY ATTENTION: EL FIELD AND OCCUPATIONS</DIV>
<DIV>My input file adhere here:</DIV>
<DIV>&CONTROL<BR>                 calculation = 'relax' ,<BR>                restart_mode = 'from_scratch' ,<BR>                  pseudo_dir = './' ,<BR>                      prefix = 'ZnO' ,<BR>                       nstep = 250 ,<BR>                     tprnfor = .true. ,<BR>                    lelfield = .true. ,<BR>                   nberrycyc = 1 ,<BR>                        gdir = 3 ,<BR> /<BR> &SYSTEM<BR>                       ibrav = 14,<BR>                   celldm(1) = 18.6286,<BR>                   celldm(2) = 0.6666667,<BR>                   celldm(3) = 1.0733333,<BR>                   celldm(4) = 0,<BR>                   celldm(5) = 0,<BR>                   celldm(6) = -0.5,<BR>                         nat = 48,<BR>                        ntyp = 3,<BR>                     ecutwfc = 30 ,<BR>                     ecutrho = 300 ,<BR>                       nosym = .true. ,<BR>                 occupations = 'smearing' ,<BR>                     degauss = 0.008 ,<BR>                    smearing = 'gaussian' ,<BR>                       nspin = 2 ,<BR>   starting_magnetization(1) = 0.5,<BR>   starting_magnetization(2) = 0.5,<BR>   starting_magnetization(3) = 0.5,<BR>                 lda_plus_u = .false. ,<BR> /<BR> &ELECTRONS<BR>                    conv_thr = 1.D-7 ,<BR>                 mixing_mode = 'plain' ,<BR>                 mixing_beta = 0.2 ,<BR>                 startingwfc = 'random' ,<BR>                      efield = 0 ,<BR> /<BR> &IONS<BR>                ion_dynamics = 'bfgs' ,<BR>                 phase_space = 'full' ,<BR> /<BR>ATOMIC_SPECIES<BR>    O   15.00000  O.pbe-rrkjus.UPF<BR>   Zn   65.00000  Zn.pbe-van.UPF<BR>   Mn   54.94000  Mn.pbe-sp-van.UPF<BR>ATOMIC_POSITIONS angstrom<BR>   Zn      0.000000000    1.875966909    0.000000000    1  1  1<BR>    O      0.000000000    1.875966909    1.991601344    1  1  1</DIV>
<DIV>....................................................<BR>K_POINTS automatic<BR>  3 3 3   1 1 1<BR>I don't know why after I add the electric field ,the speed of relax is so slow ?</DIV>
<DIV>Any advice will be appreciated !</DIV>
<DIV><BR>--<BR></DIV>
<DIV>
<DIV>Best regards</DIV>
<DIV> </DIV>
<DIV>Q.J.Wang</DIV>
<DIV> </DIV>
<DIV>XiangTan University </DIV></DIV><br><br><span title="neteasefooter"/><hr/>
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