Dear experts, I am trying to do vc-relax for my 2D systems made of C, B and N. Two different pseudo potentials gave me totally two different results, NORMCONS LDA gave me unstable structure but ULTRASOFT LDA gave me otherwise. Then I took the known 2D boron-nitride system to investigate further and again I got two different outcomes (which I attached below). Am I doing something wrong? or am I missing something? If not then which one I should believe out of the twos.
Your help will be much appreciated. Thanks in advance, Regards, -- Manoar Hossain Research Scholar School of Physical Sciences National Institute of Science Education and Research (NISER) Bhubaneswar, Jatni, Khurda, Odisha, 752050, INDIA
---------------------------------------------------------------------- INPUT: ---------------------------------------------------------------------- &CONTROL prefix = 'bn5x5' calculation = 'vc-relax' title = 'vc-relax_calculation' restart_mode = 'from_scratch' pseudo_dir = '/home/mhossain/pseudo_potential/' outdir = './tmp' verbosity = 'high' tstress = .true. tprnfor = .true. etot_conv_thr = 1.0D-6 forc_conv_thr = 1.0D-5 nstep = 900 wf_collect = .true. / &SYSTEM ibrav = 0 nat = 50 ntyp = 2 ecutwfc = 50.0 ecutrho = 200.0 occupations = 'smearing' degauss = 0.002 / &ELECTRONS conv_thr = 1.D-8 mixing_beta = 0.3D0 diagonalization = 'cg' / &IONS / &CELL cell_dofree = '2Dxy' / ATOMIC_SPECIES B 10.8110 B.pz-vbc.UPF N 14.0067 N.pz-vbc.UPF K_POINTS {automatic} 6 6 1 0 0 0 CELL_PARAMETERS {angstrom} 10.776594 6.221869 0.000000 10.776594 -6.221869 0.000000 0.000000 0.000000 11.000000 ATOMIC_POSITIONS {angstrom} B 1.43687916 1.12152101E-07 5.38600159 N 2.87375832 1.12152101E-07 5.48600197 B 3.59219837 1.24437380 5.48600197 N 5.02907658 1.24437380 5.58600235 B 5.74751663 2.48874760 5.48600197 N 7.18439674 2.48874760 5.48600197 B 7.90283394 3.73312163 5.48600197 N 9.33971596 3.73312163 5.38600159 B 10.0581532 4.97749519 5.48600197 N 11.4950314 4.97749519 5.58600235 B 3.59219837 -1.24437380 5.48600197 N 5.02907658 -1.24437380 5.48600197 B 5.74751663 1.12152101E-07 5.38600159 N 7.18439674 1.12152101E-07 5.58600235 B 7.90283394 1.24437380 5.48600197 N 9.33971596 1.24437380 5.48600197 B 10.0581532 2.48874760 5.48600197 N 11.4950314 2.48874760 5.58600235 B 12.2134724 3.73312163 5.48600197 N 13.6503506 3.73312163 5.38600159 B 5.74751663 -2.48874760 5.58600235 N 7.18439674 -2.48874760 5.48600197 B 7.90283394 -1.24437380 5.48600197 N 9.33971596 -1.24437380 5.58600235 B 10.0581532 1.12152101E-07 5.48600197 N 11.4950314 1.12152101E-07 5.38600159 B 12.2134724 1.24437380 5.58600235 N 13.6503506 1.24437380 5.38600159 B 14.3687916 2.48874760 5.48600197 N 15.8056698 2.48874760 5.58600235 B 7.90283394 -3.73312163 5.48600197 N 9.33971596 -3.73312163 5.48600197 B 10.0581532 -2.48874760 5.58600235 N 11.4950314 -2.48874760 5.48600197 B 12.2134724 -1.24437380 5.48600197 N 13.6503506 -1.24437380 5.58600235 B 14.3687916 1.12152101E-07 5.48600197 N 15.8056698 1.12152101E-07 5.48600197 B 16.5241127 1.24437380 5.48600197 N 17.9609909 1.24437380 5.48600197 B 10.0581532 -4.97749519 5.48600197 N 11.4950314 -4.97749519 5.58600235 B 12.2134724 -3.73312163 5.48600197 N 13.6503506 -3.73312163 5.48600197 B 14.3687916 -2.48874760 5.58600235 N 15.8056698 -2.48874760 5.48600197 B 16.5241127 -1.24437380 5.58600235 N 17.9609909 -1.24437380 5.38600159 B 18.6794281 1.12152101E-07 5.48600197 N 20.1163101 1.12152101E-07 5.58600235 ---------------------------------------------------------------------- OUTPUT: ---------------------------------------------------------------------- Begin final coordinates new unit-cell volume = 7664.85213 a.u.^3 ( 1135.81390 Ang^3 ) density = 0.90708 g/cm^3 CELL_PARAMETERS (angstrom) 10.442020917 6.021295880 0.000000000 9.500163008 -4.410306891 0.000000000 0.000000000 0.000000000 11.000000000 ATOMIC_POSITIONS (angstrom) B 1.2567126289 0.2335600546 4.7681718106 N 2.5660987721 0.3759260211 4.2672758261 B 3.3451201276 1.4377954998 4.7684766783 N 4.6543180800 1.5803917048 4.2671749294 B 5.4336780675 2.6418948586 4.7687381379 N 6.7428872894 2.7845347029 4.2673591084 B 7.5220340655 3.8462572618 4.7686357844 N 8.8312441054 3.9886274619 4.2672566715 B 9.6103115573 5.0506532608 4.7680504968 N 10.9196795639 5.1929531062 4.2670266094 B 3.2748325243 -0.8531042412 4.1802964433 N 4.6753199528 -0.8686899363 4.3408435755 B 5.3630777888 0.3513451800 4.1805998703 N 6.7635208781 0.3356243453 4.3411785721 B 7.4515635381 1.5554751391 4.1804517244 N 8.8520659312 1.5395476533 4.3403479264 B 9.5399814099 2.7596039237 4.1800442285 N 10.9405361877 2.7438699752 4.3400745935 B 11.6284227621 3.9639085622 4.1799970214 N 13.0289136825 3.9481241295 4.3401984643 B 5.1404340188 -1.6755299279 5.4110901035 N 6.3990918603 -1.4455456708 5.9998720598 B 7.2285535609 -0.4709665886 5.4116501543 N 8.4877369424 -0.2413738224 5.9994486230 B 9.3172256137 0.7328534526 5.4107145848 N 10.5764176162 0.9622957563 5.9984799749 B 11.4058416497 1.9367949529 5.4101131189 N 12.6649805849 2.1661677626 5.9980304469 B 13.4943215189 3.1409537427 5.4101086831 N 14.7532433855 3.3705474689 5.9984632011 B 6.9820319847 -2.4563731942 6.8066452818 N 8.3707867233 -2.4517097200 7.0585343908 B 9.0704700883 -1.2521020408 6.8064567603 N 10.4591628720 -1.2474708012 7.0585008334 B 11.1590075203 -0.0480811479 6.8060136056 N 12.5476306814 -0.0433676281 7.0585004548 B 13.2474698471 1.1560021077 6.8059022493 N 14.6360625804 1.1608111687 7.0586730233 B 15.3357944059 2.3602726933 6.8061142212 N 16.7244403360 2.3652922946 7.0586321312 B 8.9824895798 -3.5125907302 6.3309414921 N 10.2942236794 -3.3744060189 5.8372140866 B 11.0709936912 -2.3086292419 6.3313909813 N 12.3827705221 -2.1705001576 5.8378114151 B 13.1596441696 -1.1046992263 6.3318423609 N 14.4715584334 -0.9668002716 5.8384681925 B 15.2481184037 0.0994813356 6.3320239880 N 16.5597300638 0.2379627825 5.8380001542 B 17.3363014442 1.3042846842 6.3313437322 N 18.6477193473 1.4428508790 5.8369223827 End final coordinates
---------------------------------------------------------------------- INPUT ---------------------------------------------------------------------- &CONTROL prefix = 'bn5x5' calculation = 'vc-relax' title = 'vc-relax_calculation' restart_mode = 'from_scratch' pseudo_dir = '/home/mhossain/pseudo_potential/' outdir = './tmp' verbosity = 'high' tstress = .true. tprnfor = .true. etot_conv_thr = 1.0D-6 forc_conv_thr = 1.0D-5 nstep = 900 wf_collect = .true. / &SYSTEM ibrav = 0 nat = 50 ntyp = 2 ecutwfc = 50.0 ecutrho = 400.0 occupations = 'smearing' degauss = 0.002 / &ELECTRONS conv_thr = 1.D-8 mixing_beta = 0.1D0 diagonalization = 'cg' / &IONS / &CELL cell_dofree = '2Dxy' / ATOMIC_SPECIES B 10.8110 B.pz-n-rrkjus_psl.0.1.UPF N 14.0067 N.pz-n-rrkjus_psl.0.1.UPF K_POINTS {automatic} 6 6 1 0 0 0 CELL_PARAMETERS {angstrom} 10.775810000 6.221410000 0.000000000 10.775810000 -6.221410000 0.000000000 0.000000000 0.000000000 11.000000000 ATOMIC_POSITIONS {angstrom} B 1.4367861559 -0.0001216996 5.4972165773 N 2.8735300736 -0.0001539411 5.4983098688 B 3.5919269794 1.2441554309 5.5014177296 N 5.0286609776 1.2441694106 5.5003051090 B 5.7470144279 2.4885570383 5.4992979728 N 7.1837748697 2.4885743668 5.4952164430 B 7.9022852618 3.7328348839 5.4937568113 N 9.3390602401 3.7328282737 5.4910149204 B 10.0573311183 4.9771469810 5.4931171322 N 11.4940544584 4.9770795209 5.4914226164 B 3.5919219676 -1.2444996450 5.4967536888 N 5.0287004702 -1.2444419325 5.5001411452 B 5.7470963562 -0.0002255097 5.5007575049 N 7.1839435263 -0.0000780164 5.5016166021 B 7.9022392798 1.2442800414 5.4979459247 N 9.3390193023 1.2442900733 5.4972916759 B 10.0574627400 2.4885325288 5.4917453341 N 11.4941818871 2.4885094230 5.4898466479 B 12.2124506398 3.7327869962 5.4912978067 N 13.6491756333 3.7327755244 5.4934006154 B 5.7471597764 -2.4887299479 5.5010312491 N 7.1839917079 -2.4885717031 5.5053740427 B 7.9024113878 -1.2443022743 5.5045226849 N 9.3391913674 -1.2442186885 5.5076929983 B 10.0575342723 0.0001218394 5.5031697142 N 11.4942012683 0.0001511885 5.5034628697 B 12.2126321966 1.2444018521 5.4959523163 N 13.6493867751 1.2443334840 5.4969228375 B 14.3676658171 2.4885546663 5.4957955268 N 15.8044522235 2.4885713025 5.4985449184 B 7.9024379595 -3.7328128912 5.5059918681 N 9.3391962837 -3.7327826072 5.5087941635 B 10.0576233659 -2.4884663401 5.5106270928 N 11.4943657192 -2.4884302421 5.5105619979 B 12.2125855156 -1.2440628536 5.5075275697 N 13.6492897969 -1.2441423293 5.5032439955 B 14.3677370956 0.0001009373 5.4993720220 N 15.8044942197 0.0000216584 5.4995334680 B 16.5228813617 1.2443009749 5.5009406026 N 17.9596728740 1.2443822316 5.5022497549 B 10.0575114438 -4.9771150824 5.5033160365 N 11.4942789617 -4.9771339761 5.5044525664 B 12.2126494637 -3.7328147363 5.5076362568 N 13.6493863550 -3.7328851604 5.5054266203 B 14.3676006840 -2.4884061785 5.5033046093 N 15.8043760865 -2.4885599665 5.5003200183 B 16.5228629268 -1.2442831299 5.4987691638 N 17.9597124792 -1.2442491052 5.4965069251 B 18.6780213632 0.0000733819 5.4990562544 N 20.1148290960 0.0000705882 5.4981288900 ---------------------------------------------------------------------- OUTPUT ---------------------------------------------------------------------- Begin final coordinates new unit-cell volume = 9953.60596 a.u.^3 ( 1474.97223 Ang^3 ) density = 0.69850 g/cm^3 CELL_PARAMETERS (angstrom) 10.776084968 6.221572523 0.000000000 10.776084806 -6.221572242 0.000000000 0.000000000 0.000000000 11.000000000 ATOMIC_POSITIONS (angstrom) B 1.4368243426 0.0000176848 5.4995216472 N 2.8736320591 0.0000188746 5.4991298136 B 3.5920396512 1.2443459687 5.5004738880 N 5.0288581113 1.2443416620 5.4999032964 B 5.7472658564 2.4886457644 5.4996284930 N 7.1840912314 2.4886424811 5.4983875989 B 7.9024916247 3.7329432016 5.4973135848 N 9.3393082016 3.7329414559 5.4966408511 B 10.0577049429 4.9772567126 5.4977694206 N 11.4945155678 4.9772593867 5.4979758576 B 3.5920376291 -1.2442733144 5.4979536841 N 5.0288433638 -1.2442949248 5.4991017655 B 5.7472517381 0.0000434061 5.5000559221 N 7.1840601570 0.0000162639 5.5012454630 B 7.9024786159 1.2443215239 5.4994132939 N 9.3392979303 1.2443124466 5.4986628318 B 10.0577028956 2.4886174054 5.4974373865 N 11.4945244867 2.4886235693 5.4976088681 B 12.2129165774 3.7329488598 5.4972229035 N 13.6497327402 3.7329511379 5.4967947627 B 5.7472344997 -2.4886000177 5.5005282295 N 7.1840334213 -2.4886280578 5.5031223385 B 7.9024424265 -1.2443037720 5.5027911033 N 9.3392579165 -1.2443253813 5.5029186265 B 10.0576706118 -0.0000202589 5.5003944937 N 11.4944987150 -0.0000168471 5.4998070731 B 12.2129020898 1.2442911981 5.4986767011 N 13.6497182929 1.2443089744 5.4990089490 B 14.3681194076 2.4886358372 5.4981057683 N 15.8049207986 2.4886344565 5.4994268334 B 7.9024325775 -3.7329420519 5.5025916117 N 9.3392472694 -3.7329599178 5.5033094924 B 10.0576496555 -2.4886401305 5.5032727965 N 11.4944637815 -2.4886414222 5.5027912526 B 12.2128900672 -1.2443401340 5.5018531257 N 13.6497026694 -1.2443137395 5.5025102619 B 14.3681176923 -0.0000215551 5.5006855836 N 15.8049281618 0.0000015328 5.4999946192 B 16.5233255052 1.2443130803 5.4999303092 N 17.9601346366 1.2443062101 5.5005232133 B 10.0576690985 -4.9772613474 5.5015012009 N 11.4944733661 -4.9772580255 5.5015322540 B 12.2128945806 -3.7329449989 5.5024371747 N 13.6496989647 -3.7329275948 5.5022283848 B 14.3681260069 -2.4886378114 5.5021330514 N 15.8049446533 -2.4886134185 5.5004726202 B 16.5233455615 -1.2443216084 5.4993781464 N 17.9601630033 -1.2443157126 5.4976809510 B 18.6785530401 -0.0000037707 5.4989932834 N 20.1153643645 -0.0000096277 5.4992603789 End final coordinates
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