Dear all I am doing NEB calculation to find the MEP between two states using version neb-5.0.2. First, I want to get the path trajectory using no-CI and after 10-15 iterations, if the path trajectory is stabilized, I will use CI. But after 2nd iteration in my no-CI calculation, I am getting zero activation energy. My system is Ga terminated surface of GaN(0001) and one N atom is diffusing from one fcc site to another for which I am calculating MEP. Input and output files are attached. (The output is not complete since job is still running). Can anyone clarify why activation energy is zero?
Thank you for your time Manjusha IIT Kanpur India Manjusha Research Scholar Deptt. of Chemistry IIT Kanpur,Kanpur -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140417/09cfe119/attachment.html -------------- next part -------------- BEGIN BEGIN_PATH_INPUT &PATH restart_mode = 'from_scratch', string_method = 'neb', nstep_path = 20, ds = 1.0D0, opt_scheme = "broyden", num_of_images = 6, k_max = 0.6D0, k_min = 0.4D0, path_thr = 0.1D0, / END_PATH_INPUT BEGIN_ENGINE_INPUT &CONTROL prefix = "symm_NfccNEB", outdir = "/home/pinku/tmp/", pseudo_dir = "/home/pinku/pseudopotentials/", / &SYSTEM ibrav = 0 , celldm(1) = 6.088, nat = 53 , ntyp = 3 , ecutwfc = 60.0 , ecutrho = 480.0 , input_dft = 'PBE' , occupations = 'smearing', smearing = 'methfessel-paxton' , degauss = 0.05 / &ELECTRONS conv_thr = 1.D-6, mixing_mode = 'local-TF', mixing_beta = 0.5D0 / &IONS ion_dynamics = 'bfgs' / ATOMIC_SPECIES Ga 69.723 Ga.pbe-n-van.UPF N 14.006 N.pbe-van_ak.UPF H 1.0079 H.pz-vbc_075.UPF K_POINTS (automatic) 2 2 1 0 0 0 CELL_PARAMETERS {hexagonal} 2.00 0.00 0.00 1.00 1.732 0.00 0.00 0.00 9.756 BEGIN_POSITIONS FIRST_IMAGE ATOMIC_POSITIONS {crystal} H 0.000000000 0.000000000 0.196479930 0 0 0 H 0.000000000 0.500000000 0.196479930 0 0 0 H 0.500000000 0.000000000 0.196479930 0 0 0 H 0.500000000 0.500000000 0.196479930 0 0 0 N 0.000000000 0.000000000 0.229502345 0 0 0 N 0.000000000 0.500000000 0.229502345 0 0 0 N 0.500000000 0.000000000 0.229502345 0 0 0 N 0.500000000 0.500000000 0.229502345 0 0 0 Ga 0.166666666 0.166666666 0.249992062 0 0 0 Ga 0.166666666 0.666666666 0.249992062 0 0 0 Ga 0.666666666 0.166666666 0.249992062 0 0 0 Ga 0.666666666 0.666666666 0.249992062 0 0 0 N 0.166666666 0.166666666 0.312865782 0 0 0 N 0.166666666 0.666666666 0.312865782 0 0 0 N 0.666666666 0.166666666 0.312865782 0 0 0 N 0.666666666 0.666666666 0.312865782 0 0 0 Ga 0.000000000 0.000000000 0.333276902 0 0 0 Ga 0.000000000 0.500000000 0.333276902 0 0 0 Ga 0.500000000 0.000000000 0.333276902 0 0 0 Ga 0.500000000 0.500000000 0.333276902 0 0 0 N 0.000000000 0.000000000 0.396156112 0 0 0 N 0.000000000 0.500000000 0.396156112 0 0 0 N 0.500000000 0.000000000 0.396156112 0 0 0 N 0.500000000 0.500000000 0.396156112 0 0 0 Ga 0.166666666 0.166666666 0.416443231 0 0 0 Ga 0.166666666 0.666666666 0.416443231 0 0 0 Ga 0.666666666 0.166666666 0.416443231 0 0 0 Ga 0.666666666 0.666666666 0.416443231 0 0 0 N 0.166666666 0.166666666 0.479347469 0 0 0 N 0.166666666 0.666666666 0.479347469 0 0 0 N 0.666666666 0.166666666 0.479347469 0 0 0 N 0.666666666 0.666666666 0.479347469 0 0 0 Ga 0.000000000 0.000000000 0.499538888 Ga 0.000000000 0.500000000 0.499538888 Ga 0.500000000 0.000000000 0.499538888 Ga 0.500000000 0.500000000 0.499538888 N 0.000000000 0.000000000 0.562604521 N 0.000000000 0.500000000 0.562604521 N 0.500000000 0.000000000 0.562604521 N 0.500000000 0.500000000 0.562604521 Ga 0.166666666 0.166666666 0.582839633 Ga 0.166666666 0.666666666 0.582839633 Ga 0.666666666 0.166666666 0.582839633 Ga 0.666666666 0.666666666 0.582839633 N 0.166666666 0.166666666 0.646698312 N 0.166666666 0.666666666 0.646698312 N 0.666666666 0.166666666 0.646698312 N 0.666666666 0.666666666 0.646698312 Ga 0.000000000 0.000000000 0.667589406 Ga 0.000000000 0.500000000 0.667589406 Ga 0.500000000 0.000000000 0.667589406 Ga 0.500000000 0.500000000 0.667589406 N 0.333333333 0.333333333 0.731223019 LAST_IMAGE ATOMIC_POSITIONS {crystal} H 0.000000000 0.000000000 0.196479930 0 0 0 H 0.000000000 0.500000000 0.196479930 0 0 0 H 0.500000000 0.000000000 0.196479930 0 0 0 H 0.500000000 0.500000000 0.196479930 0 0 0 N 0.000000000 0.000000000 0.229502345 0 0 0 N 0.000000000 0.500000000 0.229502345 0 0 0 N 0.500000000 0.000000000 0.229502345 0 0 0 N 0.500000000 0.500000000 0.229502345 0 0 0 Ga 0.166666666 0.166666666 0.249992062 0 0 0 Ga 0.166666666 0.666666666 0.249992062 0 0 0 Ga 0.666666666 0.166666666 0.249992062 0 0 0 Ga 0.666666666 0.666666666 0.249992062 0 0 0 N 0.166666666 0.166666666 0.312865782 0 0 0 N 0.166666666 0.666666666 0.312865782 0 0 0 N 0.666666666 0.166666666 0.312865782 0 0 0 N 0.666666666 0.666666666 0.312865782 0 0 0 Ga 0.000000000 0.000000000 0.333276902 0 0 0 Ga 0.000000000 0.500000000 0.333276902 0 0 0 Ga 0.500000000 0.000000000 0.333276902 0 0 0 Ga 0.500000000 0.500000000 0.333276902 0 0 0 N 0.000000000 0.000000000 0.396156112 0 0 0 N 0.000000000 0.500000000 0.396156112 0 0 0 N 0.500000000 0.000000000 0.396156112 0 0 0 N 0.500000000 0.500000000 0.396156112 0 0 0 Ga 0.166666666 0.166666666 0.416443231 0 0 0 Ga 0.166666666 0.666666666 0.416443231 0 0 0 Ga 0.666666666 0.166666666 0.416443231 0 0 0 Ga 0.666666666 0.666666666 0.416443231 0 0 0 N 0.166666666 0.166666666 0.479347469 0 0 0 N 0.166666666 0.666666666 0.479347469 0 0 0 N 0.666666666 0.166666666 0.479347469 0 0 0 N 0.666666666 0.666666666 0.479347469 0 0 0 Ga 0.000000000 0.000000000 0.499538888 Ga 0.000000000 0.500000000 0.499538888 Ga 0.500000000 0.000000000 0.499538888 Ga 0.500000000 0.500000000 0.499538888 N 0.000000000 0.000000000 0.562604521 N 0.000000000 0.500000000 0.562604521 N 0.500000000 0.000000000 0.562604521 N 0.500000000 0.500000000 0.562604521 Ga 0.166666666 0.166666666 0.582839633 Ga 0.166666666 0.666666666 0.582839633 Ga 0.666666666 0.166666666 0.582839633 Ga 0.666666666 0.666666666 0.582839633 N 0.166666666 0.166666666 0.646698312 N 0.166666666 0.666666666 0.646698312 N 0.666666666 0.166666666 0.646698312 N 0.666666666 0.666666666 0.646698312 Ga 0.000000000 0.000000000 0.667589406 Ga 0.000000000 0.500000000 0.667589406 Ga 0.500000000 0.000000000 0.667589406 Ga 0.500000000 0.500000000 0.667589406 N 0.833333333 0.333333333 0.731223019 END_POSITIONS END_ENGINE_INPUT END -------------- next part -------------- Program NEB v.5.0.2 starts on 15Apr2014 at 9:23:11 This program is part of the open-source Quantum ESPRESSO suite for quantum simulation of materials; please cite "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009); URL http://www.quantum-espresso.org";, in publications or presentations arising from this work. More details at http://www.quantum-espresso.org/quote.php Parallel version (MPI), running on 18 processors R & G space division: proc/nbgrp/npool/nimage = 18 Warning: card &IONS ignored Warning: card ION_DYNAMICS = 'BFGS' ignored Warning: card / ignored IMPORTANT: XC functional enforced from input : Exchange-correlation = PBE ( 1 4 3 4 0) EXX-fraction = 0.00 Any further DFT definition will be discarded Please, verify this is what you really want file H.pz-vbc_075.UPF: wavefunction(s) 1S renormalized Warning: card &IONS ignored Warning: card ION_DYNAMICS = 'BFGS' ignored Warning: card / ignored IMPORTANT: XC functional enforced from input : Exchange-correlation = PBE ( 1 4 3 4 0) EXX-fraction = 0.00 Any further DFT definition will be discarded Please, verify this is what you really want file H.pz-vbc_075.UPF: wavefunction(s) 1S renormalized initial path length = 6.0880 bohr initial inter-image distance = 1.2176 bohr string_method = neb restart_mode = from_scratch opt_scheme = broyden num_of_images = 6 nstep_path = 10 CI_scheme = no-CI first_last_opt = F use_freezing = F ds = 1.0000 a.u. k_max = 0.6000 a.u. k_min = 0.4000 a.u. suggested k_max = 0.6169 a.u. suggested k_min = 0.4112 a.u. path_thr = 0.1000 eV / A ------------------------------ iteration 1 ------------------------------ tcpu = 0.3 self-consistency for image 1 tcpu = 3754.0 self-consistency for image 2 tcpu = 9381.5 self-consistency for image 3 tcpu = 14810.5 self-consistency for image 4 tcpu = 20471.4 self-consistency for image 5 tcpu = 26323.9 self-consistency for image 6 activation energy (->) = 0.036522 eV activation energy (<-) = 0.036521 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64917.3612196 3.130575 F 3 -64917.3326471 2.778883 F 4 -64917.3326448 2.778657 F 5 -64917.3612169 3.130575 F 6 -64917.3691661 3.119165 T path length = 6.088 bohr inter-image distance = 1.218 bohr ------------------------------ iteration 2 ------------------------------ tcpu = 30737.4 self-consistency for image 2 tcpu = 34000.0 self-consistency for image 3 tcpu = 37194.2 self-consistency for image 4 tcpu = 40348.8 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64917.6300552 3.984277 F 3 -64917.5735247 2.541398 F 4 -64917.5729921 2.541976 F 5 -64917.6303398 3.977213 F 6 -64917.3691661 3.119165 T path length = 6.098 bohr inter-image distance = 1.220 bohr ------------------------------ iteration 3 ------------------------------ tcpu = 43492.2 self-consistency for image 2 tcpu = 47366.5 self-consistency for image 3 tcpu = 50716.1 self-consistency for image 4 tcpu = 54090.0 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64918.0579044 2.757654 F 3 -64917.9360578 2.187571 F 4 -64917.9356208 2.187656 F 5 -64918.0580502 2.758018 F 6 -64917.3691661 3.119165 T path length = 6.164 bohr inter-image distance = 1.233 bohr ------------------------------ iteration 4 ------------------------------ tcpu = 57928.4 self-consistency for image 2 tcpu = 62313.7 self-consistency for image 3 tcpu = 66138.2 self-consistency for image 4 tcpu = 69956.4 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64918.6842995 2.822266 F 3 -64918.3336882 1.072720 F 4 -64918.3335107 1.073567 F 5 -64918.6849020 2.820651 F 6 -64917.3691661 3.119165 T path length = 6.426 bohr inter-image distance = 1.285 bohr ------------------------------ iteration 5 ------------------------------ tcpu = 74166.9 self-consistency for image 2 tcpu = 78478.8 self-consistency for image 3 tcpu = 82233.7 self-consistency for image 4 tcpu = 85980.2 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64919.2464153 2.881492 F 3 -64918.4311601 1.738661 F 4 -64918.4310973 1.738617 F 5 -64919.2471462 2.878638 F 6 -64917.3691661 3.119165 T path length = 6.924 bohr inter-image distance = 1.385 bohr ------------------------------ iteration 6 ------------------------------ tcpu = 90183.5 self-consistency for image 2 tcpu = 94229.5 self-consistency for image 3 tcpu = 97420.5 self-consistency for image 4 tcpu = 100612.6 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen 1 -64917.3691663 3.118784 T 2 -64919.6863336 2.357326 F 3 -64918.3306026 3.752568 F 4 -64918.3307659 3.754808 F 5 -64919.6865281 2.355640 F 6 -64917.3691661 3.119165 T path length = 7.684 bohr inter-image distance = 1.537 bohr ------------------------------ iteration 7 ------------------------------ tcpu = 104646.2 self-consistency for image 2 tcpu = 108199.4 self-consistency for image 3 tcpu = 111993.6 self-consistency for image 4 tcpu = 115757.4 self-consistency for image 5 activation energy (->) = 0.000000 eV activation energy (<-) = 0.000000 eV image energy (eV) error (eV/A) frozen =------------------------------------------------------------------------------=
