<div dir="ltr"><div><div><div><div><div><div>Dear QE experts <br><br></div>i am doing adsorption of bromine in 3*3 graphene sheet. But there comes an error after one scf cycle which is mentioned below,<br><br><br><br>Writing output data file bromine_relax_pb.save<br>     NEW-OLD atomic charge density approx. for the potential<br><br>     negative rho (up, down):  1.894E-04 0.000E+00<br><br>     total cpu time spent up to now is     3015.2 secs<br><br>     per-process dynamical memory:   765.2 Mb<br><br>     Self-consistent Calculation<br><br>     iteration #  1     ecut=    45.00 Ry     beta=0.60<br>     Davidson diagonalization with overlap<br><br> <br>     Error in routine cdiaghg (332):<br>     S matrix not positive definite<br> <br><br>     stopping ...<br><br></div>Here is the input file i have used<br><br>&control<br>calculation='relax'    <br>restart_mode='from_scratch'<br>prefix='bromine_relax_pb'<br>outdir='/home/physics/Downloads/graphene/bromine',<br>pseudo_dir = '/home/physics/Downloads/graphene/pseudopotentials',<br>tstress=.true.<br>tprnfor=.true.<br>verbosity='high'<br>forc_conv_thr=1.0d-3<br>etot_conv_thr=1.0d-4<br>/<br>&SYSTEM<br>ibrav=4<br>celldm(1)=13.95<br>celldm(3)=2.71<br>nat=20<br>ntyp=2<br>ecutwfc=45.0<br>ecutrho=450<br>occupations='smearing'<br>smearing='mv'<br>degauss=0.002<br>vdw_corr='dft-d'<br>/ <br>&ELECTRONS<br>diagonalization='david'<br>mixing_mode='plain'<br>electron_maxstep = 100<br>mixing_beta=0.6<br>conv_thr = 1.0D-8<br>/<br>&IONS<br>ion_dynamics='bfgs'<br>/<br><br>ATOMIC_SPECIES<br>C 12.011 C.pbe-rrkjus.UPF<br>Br 79.90 Br.pbe-n-rrkjus_psl.0.2.UPF<br>ATOMIC_POSITIONS (angstrom)<br>C  0.001428319  -0.002221684   0.000000000<br>C  1.231420386   0.708643125   0.000000000<br>C  2.462100004  -0.002217662   0.000000000<br>C  3.692093444   0.708644819   0.000000000<br>C  -1.228907612  2.128792409   0.000000000<br>C  0.001083491   2.839646136   0.000000000<br>C  1.231766190   2.128786536   0.000000000<br>C  2.461756350   2.839644042   0.000000000<br>C  4.922778865  -0.002223457   0.000000000<br>C  6.152768802   0.708640258   0.000000000<br>C  3.692440675   2.128788864   0.000000000<br>C  4.922431282   2.839647087   0.000000000<br>C  -2.459244768  4.259790447   0.000000000<br>C  -1.229251320  4.970648411   0.000000000<br>C  0.001427750   4.259792429   0.000000000<br>C  1.231421212   4.970653053   0.000000000<br>C  2.462102410   4.259795383   0.000000000<br>C  3.692093014   4.970654542   0.000000000<br>Br 2.461756350   2.558726619   3.500000000<br>Br 2.461756350   0.278726619   3.500000000<br><br>K_POINTS {automatic}<br>5 5 1 0 0 0<br><br><br></div>With Best Regards<br></div>Nipesh Dulal<br></div>Tribhuwan University<br></div>Kathmandu , Nepal<br></div>