<div dir="ltr"><div class="gmail_quote">Dear Sir<br></div><div class="gmail_quote"><div dir="ltr">I am doing vc-relax calculation but getting following error<br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<wbr>%%%%%%%%<br>     Error in routine  invmat (1):<br>      singular matrix<br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<wbr>%%%%%%%%<br><br>     stopping ...<br><br clear="all"><div>My input file is<br>******************************<br>&CONTROL<br>!calculation = "scf",<br>calculation = 'vc-relax',<br>restart_mode='from_scratch',<br>!restart_mode='restart',<br>prefix = "ZNO",<br>pseudo_dir = "/home/external/aca/pradips/<wbr>qmespresso/potentials/",<br>outdir = "TMP_DIR",<br>!nstep=1000,<br>forc_conv_thr = 1.0D-3,<br>/<br>&SYSTEM<br>ibrav=0,<br>!celldm(1) =6.330582528,<br>nat=6, ntyp= 2, tot_charge=0.0,<br>occupations='smearing', smearing='gauss', degauss=0.001,<br>ecutwfc =140.0, !better 140 if too small convergence is not acheived and if too large have memory issue<br>ecutrho =560.0, !better to keep 10 times ecutwfc<br>!nr1=60,nr2=60,nr3=1,<br>!vdw_corr='Grimme-D2'<br>vdw_corr='ts-vdW'<br>nspin=2,!1 ,2 or 4 non, spin along z,spin magnetizetion in generic direction<br>starting_magnetization(1)= 0.003,<br>/<br>&ELECTRONS<br>mixing_mode='plain',<br>mixing_beta = 0.5,<br>startingwfc='random',<br>conv_thr = 1.0d-10,<br>/<br>&IONS<br>ion_dynamics='bfgs',<br>!ion_positions='from_input',<br>! trust_radius_ini=1.0d-1,<br>!   trust_radius_max=1.0d-3,<br>/<br>&CELL<br>cell_dynamics='bfgs',<br>cell_factor=10,<br>/<br>ATOMIC_SPECIES<br>Zn 65.409 Zn.pbe-d-hgh.UPF<br>O 15.999 O.pbe-hgh.UPF<br>K_POINTS automatic<br>6 6 1 0 0 0<br>CELL_PARAMETERS angstrom<br>   1.67981234   2.90856546      -0.07019054<br>   1.67980068   2.90854117      0.07008386<br>   0.00000000   0.00000000      20.00000000<br><br>ATOMIC_POSITIONS angstrom<br>O       1.67987344      -1.02383752     7.12870557<br>O       1.67981269      0.96769655      4.81101438<br>O       1.67978262      0.91281223      2.40141545<br>Zn      1.67986016      0.91661447      7.11917516<br>Zn      1.67982409      0.97136165      4.76433684<br>Zn      1.67977360      1.02488273      2.50422980<br>******************************<wbr>******************************<wbr>****************************<span class="HOEnZb"><font color="#888888"><br><br><br></font></span></div><span class="HOEnZb"><font color="#888888"><div>-- <br><div class="m_1777981000213962511gmail_signature"><div dir="ltr"><div><div><div><div>Dr. Pradip B. Shelke<br></div>Associate Professor,<br></div>Department of Physics,<br></div>Ahmednagar College, Ahmednagar, India.<br></div><div>Contact: 9422226924<br></div></div></div>
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</div><br><br clear="all"><br>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div><div><div>Dr. Pradip B. Shelke<br></div>Associate Professor,<br></div>Department of Physics,<br></div>Ahmednagar College, Ahmednagar, India.<br></div><div>Contact: 9422226924<br></div></div></div>
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