<div dir="ltr">Hello all, <div>       I am doing vc-relax calculation for the conventional cell NbCo2. Everything going well, means convergence has been achieved with threshold 1e-8, but at the last step pressure comes with a high negative value like -134 kbar. Same case occurs for both Ultrasoft and PAW pseudopotentials. I am trying with different press_conv_thresholds,  but it comes the same every time. I am giving my input file. Pls tell me where I should change?<br><br>&CONTROL<br>  calculation = 'vc-relax'<br>  outdir = './out/'<br>  prefix = 'NbCo2'<br>  pseudo_dir = '.'<br>  verbosity = 'high'<br>  etot_conv_thr = 1e-5<br>  forc_conv_thr = 1e-4<br>/<br>&SYSTEM<br>    degauss =   1d-02<br>    ibrav = 0,                   ! Free cell definition (explicit cell parameters)<br>    nat = 24,                    ! Number of atoms in the unit cell<br>    ntyp = 2,                    ! Number of atomic species (Cr, Zr)<br>    ecutwfc = 50,                ! Wavefunction cutoff energy (Ry)<br>    ecutrho = 600, <br>    occupations = 'smearing'<br>    smearing = 'mp'  <br>/<br>&ELECTRONS<br>    conv_thr = 1.0d-8,           ! Convergence threshold for SCF iterations<br>    electron_maxstep = 250<br>    mixing_beta = 7.00000e-01,           ! Mixing parameter<br>/<br>&IONS<br>  ion_dynamics = 'bfgs'<br>/<br>&CELL<br>   cell_dofree='all'<br>   press=0.0<br>   press_conv_thr= 1d-2<br>/<br>CELL_PARAMETERS {angstrom}<br>  6.712963530000   0.000000000000   0.000000000000<br>  0.000000000000   6.712963530000   0.000000000000<br>  0.000000000000   0.000000000000   6.712963530000<br>ATOMIC_SPECIES<br>Nb     92.90638  Nb.pbe-spn-rrkjus_psl.1.0.0.UPF<br>Co     58.933195  Co.pbe-spn-rrkjus_psl.0.3.1.UPF<br>ATOMIC_POSITIONS {crystal}<br>Co  0.125000000000   0.125000000000   0.125000000000<br>Co  0.375000000000   0.375000000000   0.125000000000<br>Co  0.625000000000   0.625000000000   0.125000000000<br>Co  0.875000000000   0.875000000000   0.125000000000<br>Co  0.375000000000   0.125000000000   0.375000000000<br>Co  0.125000000000   0.375000000000   0.375000000000<br>Co  0.875000000000   0.625000000000   0.375000000000<br>Co  0.625000000000   0.875000000000   0.375000000000<br>Co  0.625000000000   0.125000000000   0.625000000000<br>Co  0.875000000000   0.375000000000   0.625000000000<br>Co  0.125000000000   0.625000000000   0.625000000000<br>Co  0.375000000000   0.875000000000   0.625000000000<br>Co  0.875000000000   0.125000000000   0.875000000000<br>Co  0.625000000000   0.375000000000   0.875000000000<br>Co  0.375000000000   0.625000000000   0.875000000000<br>Co  0.125000000000   0.875000000000   0.875000000000<br>Nb  0.500000000000   0.000000000000   0.000000000000<br>Nb  0.000000000000   0.500000000000   0.000000000000<br>Nb  0.750000000000   0.250000000000   0.250000000000<br>Nb  0.250000000000   0.750000000000   0.250000000000<br>Nb  0.000000000000   0.000000000000   0.500000000000<br>Nb  0.500000000000   0.500000000000   0.500000000000<br>Nb  0.250000000000   0.250000000000   0.750000000000<br>Nb  0.750000000000   0.750000000000   0.750000000000<br>K_POINTS {automatic}<br>    6 6 6 0 0 0                  ! Denser Monkhorst-Pack grid for better accuracy</div><div><br>Thanking you,<br>SANKHA<br><br></div></div>