[Pw_forum] Vc_Relax distorts the whole structure

[Mofrad, Amir Mehdi (MU-Student)]

Dear all,


I want to do a cell optimization on sodalite (a type of zeolite), however, after I visualize the structure in xcrysden, not only it distorts the whole cell but also the final configuration is very different (not actually sodalite) from its initial one. I put my input file in case you might need to take a look at. Any help would be thoroughly appreciated.


&CONTROL
                 calculation = 'vc-relax' ,
                restart_mode = 'from_scratch' ,
                  wf_collect = .true. ,
                      outdir = './scratch' ,
                      wfcdir = './scratch' ,
                  pseudo_dir = '/global/espresso/pseudo' ,
                      prefix = 'SOD' ,
                   verbosity = 'high' ,
               etot_conv_thr = 1e-5 ,
               forc_conv_thr = 1e-4 ,
                       nstep = 50 ,
                     tstress = .true. ,
                     tprnfor = .true. ,
 /
 &SYSTEM
                       ibrav = 0,
                         nat = 42,
                        ntyp = 4,
                     ecutwfc = 50 ,
                     ecutrho = 500 ,
 /
 &ELECTRONS
            electron_maxstep = 100,
                    conv_thr = 3e-8 ,
                 mixing_mode = 'plain' ,
                 mixing_beta = 0.7 ,
             diagonalization = 'david' ,
 /
 &IONS
                ion_dynamics = 'bfgs' ,
            trust_radius_ini = 0.5 ,
 /
&CELL
        cell_dynamics = 'bfgs',
/

CELL_PARAMETERS bohr
    16.720296750    0.000000000    0.000000000
     0.000000000   16.720296750    0.000000000
     0.000000000    0.000000000   16.720296750

ATOMIC_SPECIES
   Si   28.08600  Si.pbe-n-rrkjus_psl.0.1.UPF
    O   15.99940  O.pbe-n-rrkjus_psl.0.1.UPF
    Al  26.981539 Al.pbe-n-rrkjus_psl.0.1.UPF
   Na   22.989769 Na.pbe-sp-van_ak.UPF

ATOMIC_POSITIONS angstrom
Si   2.21200   0.00000   4.42400
Si   6.63600   0.00000   4.42400
Si   4.42400   2.21200   0.00000
Si   4.42400   6.63600   0.00000
Si   0.00000   4.42400   2.21200
Si   0.00000   4.42400   6.63600
Al   2.21200   4.42400   0.00000
Al   6.63600   4.42400   0.00000
Al   0.00000   2.21200   4.42400
Al   0.00000   6.63600   4.42400
Al   4.42400   0.00000   2.21200
Al   4.42400   0.00000   6.63600
 O   1.20864   3.83826   1.31835
 O   7.63936   5.00974   1.31835
 O   7.63936   3.83826   7.52965
 O   1.20864   5.00974   7.52965
 O   1.31835   1.20864   3.83826
 O   1.31835   7.63936   5.00974
 O   7.52965   7.63936   3.83826
 O   7.52965   1.20864   5.00974
 O   3.83826   1.31835   1.20864
 O   5.00974   1.31835   7.63936
 O   3.83826   7.52965   7.63936
 O   5.00974   7.52965   1.20864
 O   8.26226   5.63264   5.74235
 O   0.58574   3.21536   5.74235
 O   8.26226   3.21536   3.10565
 O   0.58574   5.63264   3.10565
 O   5.63264   5.74235   8.26226
 O   3.21536   5.74235   0.58574
 O   3.21536   3.10565   8.26226
 O   5.63264   3.10565   0.58574
 O   5.74235   8.26226   5.63264
 O   5.74235   0.58574   3.21536
 O   3.10565   8.26226   3.21536
 O   3.10565   0.58574   5.63264
Na   1.33074   1.33074   1.33074
Na   7.51726   1.33074   7.51726
Na   1.33074   7.51726   7.51726
Na   5.75474   5.75474   5.75474
Na   5.75474   3.09326   3.09326
Na   3.09326   5.75474   3.09326


K_POINTS automatic
 2 2 2   1 1 1




Best,


Amir M. Mofrad

Graduate Research Assistant

Chemical Engineering Department

University of Missouri
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