<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear QE users,<div class=""><br class=""></div><div class="">I’m Filippo Savazzi, a PhD student from Politecnico di Torino, Italy.</div><div class="">I’m using QE since a couple of years, and just browsing the archives of this mailing list or enquiring the mighty google I’ve been lucky enough that this is actually the first time I have to post a question.</div><div class="">Thanks everybody for the indirect support you gave me in these years.</div><div class=""><br class=""></div><div class="">I’m calculating absorption energies of oxygen on a coronene molecule, as part of a little evaluation of different available XC functionals that I’m doing. I’m calculating the absorption energy both with respect to the molecular oxygen and with atomic oxygen.</div><div class="">My problems arise when I try to calculate the energy of a single atom of oxygen using SCAN. In this case the energy diverges until the SCF fails. I have no troubles running the calculation on the actual system (coronene + bridged O), neither on a molecular oxygen (triplet O2); the issue is just localised on the single oxygen atom. My first guess was that the implementation of SCAN has either troubles in dealing with isolated systems or with spin polarization, but I ruled out these issues when I was able to calculate the single point energy of an oxygen molecule. Are you aware of any other problems using SCAN in these conditions?</div><div class="">In the following I attach the input for pw.x I’m using, as well as a brief example of the SCF part in the output. I already played with cell dimension (thinking too much vacuum could have been the problem), as well as with ecutwfc and ecutrho (so indirectly with the integration grid), and then, just to give it a chance, with the diagonalization method and beta-mixing. </div><div class=""><br class=""></div><div class="">Thank you in advance for your attention.</div><div class=""><br class=""></div><div class="">Best, </div><div class="">Filippo</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Filippo Savazzi, PhD Student</div><div class="">Politecnico di Torino, Torino, Italy</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">&CONTROL</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> calculation = ’scf',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> restart_mode='from_scratch',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> pseudo_dir = '/home/filippo/pseudo',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> outdir='./tmp_o',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> prefix='oxy',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> /</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> &SYSTEM</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> ibrav=6,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> celldm(1)=20,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> celldm(3)=1,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> nat=1,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> ntyp=1,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> input_dft='scan',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> ecutwfc=100,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> tot_magnetization=2,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> nspin=2,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> /</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> &ELECTRONS</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> diagonalization = 'cg',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> electron_maxstep = 300,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> mixing_mode = 'local-TF',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> mixing_beta = 0.7,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> conv_thr = 1.0d-7,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> /</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> &IONS</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> ion_dynamics='damp',</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> upscale=1000,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""> /</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">ATOMIC_SPECIES</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">O 15.99 O_ONCV_PBE-1.0.upf</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">ATOMIC_POSITIONS {angstrom}</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">O 0.0000 0.0000 0.0000</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class="">K_POINTS{gamma}</span></div></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class="">EXTRACT OF OUTPUT:</div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #2fff12" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">Dense grid: 540376 G-vectors FFT dimensions: ( 128, 128, 128)</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Estimated max dynamical RAM per process > 116.06 MB</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Estimated total dynamical RAM > 1.36 GB</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Generating pointlists ...</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> new r_m : 0.4125 (alat units) 8.2500 (a.u.) for type 1</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Initial potential from superposition of free atoms</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> starting charge 5.99905, renormalised to 6.00000</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> negative rho (up,down): 4.917E-05 4.917E-05</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Starting wfcs are random</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total cpu time spent up to now is 3.1 secs</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Self-consistent Calculation</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> iteration # 1 ecut= 100.00 Ry beta= 0.70</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> CG style diagonalization</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> ethr = 1.00E-02, avg # of iterations = 9.6</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> negative rho (up,down): 1.044E-03 1.363E-03</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total cpu time spent up to now is 240.5 secs</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total energy = 2429.63502350 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Harris-Foulkes estimate = -31.41616940 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> estimated scf accuracy < 3.28037744 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total magnetization = 2.00 Bohr mag/cell</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> absolute magnetization = 2.00 Bohr mag/cell</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> iteration # 2 ecut= 100.00 Ry beta= 0.70</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> CG style diagonalization</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> c_bands: 4 eigenvalues not converged</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> ethr = 1.00E-02, avg # of iterations = 13.6</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> negative rho (up,down): 2.824E-03 3.815E-03</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total cpu time spent up to now is 331.7 secs</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total energy = 33638.43350785 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Harris-Foulkes estimate = 318.68713998 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> estimated scf accuracy < 0.37936007 Ry</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> total magnetization = 2.00 Bohr mag/cell</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> absolute magnetization = 2.00 Bohr mag/cell</span></div></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono";" class=""><span style="font-variant-ligatures: no-common-ligatures; background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; font-family: "Andale Mono"; background-color: rgb(255, 255, 255);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div></body></html>