Dear Forum, I am using PWscf for interface structural optimization. The geometry relaxation on interface (LiCoO2/sulfides) seems very difficult to converge so far. Can anyone give me help? Here is my input file:

<br><br>&CONTROL<br>  calculation = "relax",<br>  prefix      = "intf66a_rlx"<br>  pseudo_dir  = "./",<br>  outdir      = "./",<br>/<br>&SYSTEM<br>  ibrav       = 14,<br>  celldm(1)   = 

61.18796,<br>  celldm(2)   = 0.18633,<br>  celldm(3)   = 0.38711,<br>  celldm(4)   = -0.22231431,<br>  celldm(5)   = -0.39398,<br>  celldm(6)   = 0.267793,<br>  nat         = 66,<br>  ntyp        = 5,<br>  ecutwfc     = 42.D0

,<br>  ecutrho     = 320.D0,<br>  occupations = "smearing",<br>  smearing    = "methfessel-paxton",<br>  degauss     = 0.05D0<br>/<br>&ELECTRONS<br>  conv_thr    = 1.D-6,<br>  mixing_beta = 0.1D0,<br>

  mixing_mode = "local-TF",<br>/<br>&IONS<br>  ion_dynamics      = "bfgs",<br>  opt_scheme        = "broyden",<br>  bfgs_ndim         = 3,<br>  trust_radius_max  = 0.8D0,<br>  pot_extrapolation = "second_order",

<br>  wfc_extrapolation = "second_order",<br>/<br>ATOMIC_SPECIES<br>P   30.9737  P.pbe-n-van.UPF<br>Li  6.941    Li.pbe-n-van.UPF<br>S   32.066   S.pbe-van_bm.UPF<br>Co  58.9332  Co.pbe-nd-rrkjus.UPF<br>O   15.9994

  O.pbe-rrkjus.UPF<br>ATOMIC_POSITIONS {angstrom}<br>........<br>K_POINTS crystal <br> 1   <br>        0.2914500000    0.5294200000   -0.2781600000    1.0<br><br>===================================================<br><br>

The output is as following:<br>    Total force =     1.677255     Total SCF correction =     0.001300<br>     Total force =     0.607898     Total SCF correction =     0.002820<br>     Total force =     0.448659     Total SCF correction =     

0.002098<br>     Total force =     0.352568     Total SCF correction =     0.001579<br>     Total force =     0.291404     Total SCF correction =     0.001432<br>     Total force =     0.254533     Total SCF correction =     

0.001601<br>     Total force =     0.233841     Total SCF correction =     0.001331<br>     Total force =     0.223115     Total SCF correction =     0.001884<br>     Total force =     0.222679     Total SCF correction =     

0.001979<br>     Total force =     0.230224     Total SCF correction =     0.001892<br>     Total force =     0.241234     Total SCF correction =     0.001275<br>     Total force =     0.252683     Total SCF correction =     

0.001494<br>     Total force =     0.266314     Total SCF correction =     0.001429<br>     Total force =     0.284588     Total SCF correction =     0.001093<br>     Total force =     0.309129     Total SCF correction =     

0.001386<br>     Total force =     0.312575     Total SCF correction =     0.001656<br>     Total force =     0.306147     Total SCF correction =     0.001511<br>     Total force =     0.280490     Total SCF correction =     

0.001399<br>     Total force =     0.261216     Total SCF correction =     0.000735<br>     Total force =     0.244781     Total SCF correction =     0.001154<br>     Total force =     0.230320     Total SCF correction =     

0.001218<br><br>Thank you in advance<br><br>Sei Ou<br>Simulatio Co.<br>Yokohama-shi, Japan<br><br><br>