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[求助]
[color=Red]k点的选取，怎么算?收敛性测试时怎么变化k点值？[/color]
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初学第一性原理，不知道k点怎么选取，怎么算?晶格常数是a=b=0.29508,c=0.46885,那么k点应取多少啊？希望路过的虫虫们指点一二，麻烦了，谢谢啦。。。 还有就是收敛性测试时怎么变化k点值？我知道收敛性测试时可以先确定k点，比如是3*3*2，截断能可以设为310,320,330,340....从而根据能量来确定截断能值。 那么如果截断能确定为340，那么k点怎么变化，可以设为3*3*1,3*3*3 2*2*1,4*4*1,4*4*2,4*4*3么？是不是一定要保证前两个数值要一样啊？ |
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毛毛虫315: 回帖置顶 2012-10-31 16:37:56
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Job started on host zouaihua at Wed Oct 31 16:00:30 2012 +-------------------------------------------------+ | | | CCC AA SSS TTTTT EEEEE PPPP | | C A A S T E P P | | C AAAA SS T EEE PPPP | | C A A S T E P | | CCC A A SSS T EEEEE P | | | +-------------------------------------------------+ | | | Welcome to Materials Studio CASTEP version 5.0 | | Ab Initio Total Energy Program | | | | Authors: | | M. Segall, M. Probert, C. Pickard, P. Hasnip, | | S. Clark, K. Refson, M. Payne | | | | Contributors: | | P. Lindan, P. Haynes, J. White, V. Milman, | | N. Govind, M. Gibson, P. Tulip, V. Cocula, | | B. Montanari, D. Quigley, M. Glover, | | L. Bernasconi, A. Perlov, M. Plummer, | | E. McNellis, J. Meyer | | | | Copyright (c) 2000 - 2009 | | | | Please cite | | | | "First principles methods using CASTEP" | | | | Zeitschrift fuer Kristallographie | | 220(5-6) pp. 567-570 (2005) | | | | S. J. Clark, M. D. Segall, C. J. Pickard, | | P. J. Hasnip, M. J. Probert, K. Refson, | | M. C. Payne | | | | in all publications arising from | | your use of CASTEP | | | +-------------------------------------------------+ This version was compiled for i686-windows-msvc2008 on Oct 22 2009 License checkout of MS_castep successful Pseudo atomic calculation performed for Ti 3s2 3p6 3d2 4s2 Converged in 36 iterations to a total energy of -1596.1726 eV Calculation parallelised over 4 nodes. K-points are distributed over 4 groups, each containing 1 nodes. ************************************ Title ************************************ CASTEP calculation from Materials Studio ***************************** General Parameters ****************************** output verbosity : normal (1) write checkpoint data to : Ti__0_0_1_.check type of calculation : single point energy stress calculation : off density difference calculation : off electron localisation func (ELF) calculation : off Hirshfeld analysis : off unlimited duration calculation timing information : on memory usage estimate : on write final potential to formatted file : off write final density to formatted file : off output length unit : A output mass unit : amu output time unit : ps output charge unit : e output energy unit : eV output force unit : eV/A output velocity unit : A/ps output pressure unit : GPa output inv_length unit : 1/A output frequency unit : cm-1 output force constant unit : eV/A**2 output volume unit : A**3 output IR intensity unit : (D/A)**2/amu output dipole unit : D output efield unit : eV/A/e wavefunctions paging : none random number generator seed : randomised (160031306) data distribution : optimal for this architecture optimization strategy : maximize speed(+++) *********************** Exchange-Correlation Parameters *********************** using functional : Perdew Burke Ernzerhof Divergence correction : off DFT+D: Semi-empirical dispersion correction : off ************************* Pseudopotential Parameters ************************** pseudopotential representation : reciprocal space **************************** Basis Set Parameters ***************************** plane wave basis set cut-off : 350.0000 eV size of standard grid : 2.3000 largest prime factor in FFT : 5 finite basis set correction : none **************************** Electronic Parameters **************************** number of electrons : 36.00 net charge of system : 0.000 net spin of system : 0.000 number of up spins : 18.00 number of down spins : 18.00 treating system as non-spin-polarized number of bands : 22 ********************* Electronic Minimization Parameters ********************** Method: Treating system as metallic with density mixing treatment of electrons, and number of SD steps : 1 and number of CG steps : 4 total energy / atom convergence tol. : 0.5000E-06 eV eigen-energy convergence tolerance : 0.6818E-07 eV max force / atom convergence tol. : ignored convergence tolerance window : 3 cycles max. number of SCF cycles : 100 number of fixed-spin iterations : 10 smearing scheme : Gaussian smearing width : 0.1000 eV Fermi energy convergence tolerance : 0.6818E-08 eV ************************** Density Mixing Parameters ************************** density-mixing scheme : Pulay max. length of mixing history : 20 charge density mixing amplitude : 0.5000 cut-off energy for mixing : 350.0 eV charge density mixing g-vector : 1.500 1/A ******************************************************************************* ------------------------------- Unit Cell ------------------------------- Real Lattice(A) Reciprocal Lattice(1/A) 2.5512550 -1.4729678 0.0000000 2.4627821 0.0000000 0.0000000 0.0000000 2.9459356 0.0000000 1.2313911 2.1328319 0.0000000 0.0000000 0.0000000 14.6384327 0.0000000 0.0000000 0.4292253 Lattice parameters(A) Cell Angles a = 2.945936 alpha = 90.000000 b = 2.945936 beta = 90.000000 c = 14.638433 gamma = 120.000000 Current cell volume = 110.020015 A**3 ------------------------------- Cell Contents ------------------------------- Total number of ions in cell = 3 Total number of species in cell = 1 Max number of any one species = 3 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx x Element Atom Fractional coordinates of atoms x x Number u v w x x----------------------------------------------------------x x Ti 1 0.333333 0.666667 0.158433 x x Ti 2 0.666667 0.333333 0.000000 x x Ti 3 0.666667 0.333333 0.316867 x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx No user defined ionic velocities ------------------------------- Details of Species ------------------------------- Mass of species in AMU Ti 47.9000015 Electric Quadrupole Moment (Barn) Ti 0.3020000 Isotope 47 Files used for pseudopotentials: Ti Ti_00PBE.usp ------------------------------- k-Points For BZ Sampling ------------------------------- MP grid size for SCF calculation is 10 10 2 Number of kpoints used = 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ + Number Fractional coordinates Weight + +-----------------------------------------------------+ + 1 0.450000 0.450000 0.250000 0.0100000 + + 2 0.450000 0.450000 -0.250000 0.0100000 + + 3 0.450000 0.350000 0.250000 0.0100000 + + 4 0.450000 0.350000 -0.250000 0.0100000 + + 5 0.450000 0.250000 0.250000 0.0100000 + + 6 0.450000 0.250000 -0.250000 0.0100000 + + 7 0.450000 0.150000 0.250000 0.0100000 + + 8 0.450000 0.150000 -0.250000 0.0100000 + + 9 0.450000 0.050000 0.250000 0.0100000 + + 10 0.450000 0.050000 -0.250000 0.0100000 + + 11 0.450000 -0.050000 0.250000 0.0100000 + + 12 0.450000 -0.050000 -0.250000 0.0100000 + + 13 0.450000 -0.150000 0.250000 0.0100000 + + 14 0.450000 -0.150000 -0.250000 0.0100000 + + 15 0.450000 -0.250000 0.250000 0.0100000 + + 16 0.450000 -0.250000 -0.250000 0.0100000 + + 17 0.450000 -0.350000 0.250000 0.0100000 + + 18 0.450000 -0.350000 -0.250000 0.0100000 + + 19 0.450000 -0.450000 0.250000 0.0100000 + + 20 0.450000 -0.450000 -0.250000 0.0100000 + + 21 0.350000 0.450000 0.250000 0.0100000 + + 22 0.350000 0.450000 -0.250000 0.0100000 + + 23 0.350000 0.350000 0.250000 0.0100000 + + 24 0.350000 0.350000 -0.250000 0.0100000 + + 25 0.350000 0.250000 0.250000 0.0100000 + + 26 0.350000 0.250000 -0.250000 0.0100000 + + 27 0.350000 0.150000 0.250000 0.0100000 + + 28 0.350000 0.150000 -0.250000 0.0100000 + + 29 0.350000 0.050000 0.250000 0.0100000 + + 30 0.350000 0.050000 -0.250000 0.0100000 + + 31 0.350000 -0.050000 0.250000 0.0100000 + + 32 0.350000 -0.050000 -0.250000 0.0100000 + + 33 0.350000 -0.150000 0.250000 0.0100000 + + 34 0.350000 -0.150000 -0.250000 0.0100000 + + 35 0.350000 -0.250000 0.250000 0.0100000 + + 36 0.350000 -0.250000 -0.250000 0.0100000 + + 37 0.350000 -0.350000 0.250000 0.0100000 + + 38 0.350000 -0.350000 -0.250000 0.0100000 + + 39 0.350000 -0.450000 0.250000 0.0100000 + + 40 0.350000 -0.450000 -0.250000 0.0100000 + + 41 0.250000 0.450000 0.250000 0.0100000 + + 42 0.250000 0.450000 -0.250000 0.0100000 + + 43 0.250000 0.350000 0.250000 0.0100000 + + 44 0.250000 0.350000 -0.250000 0.0100000 + + 45 0.250000 0.250000 0.250000 0.0100000 + + 46 0.250000 0.250000 -0.250000 0.0100000 + + 47 0.250000 0.150000 0.250000 0.0100000 + + 48 0.250000 0.150000 -0.250000 0.0100000 + + 49 0.250000 0.050000 0.250000 0.0100000 + + 50 0.250000 0.050000 -0.250000 0.0100000 + + 51 0.250000 -0.050000 0.250000 0.0100000 + + 52 0.250000 -0.050000 -0.250000 0.0100000 + + 53 0.250000 -0.150000 0.250000 0.0100000 + + 54 0.250000 -0.150000 -0.250000 0.0100000 + + 55 0.250000 -0.250000 0.250000 0.0100000 + + 56 0.250000 -0.250000 -0.250000 0.0100000 + + 57 0.250000 -0.350000 0.250000 0.0100000 + + 58 0.250000 -0.350000 -0.250000 0.0100000 + + 59 0.250000 -0.450000 0.250000 0.0100000 + + 60 0.250000 -0.450000 -0.250000 0.0100000 + + 61 0.150000 0.450000 0.250000 0.0100000 + + 62 0.150000 0.450000 -0.250000 0.0100000 + + 63 0.150000 0.350000 0.250000 0.0100000 + + 64 0.150000 0.350000 -0.250000 0.0100000 + + 65 0.150000 0.250000 0.250000 0.0100000 + + 66 0.150000 0.250000 -0.250000 0.0100000 + + 67 0.150000 0.150000 0.250000 0.0100000 + + 68 0.150000 0.150000 -0.250000 0.0100000 + + 69 0.150000 0.050000 0.250000 0.0100000 + + 70 0.150000 0.050000 -0.250000 0.0100000 + + 71 0.150000 -0.050000 0.250000 0.0100000 + + 72 0.150000 -0.050000 -0.250000 0.0100000 + + 73 0.150000 -0.150000 0.250000 0.0100000 + + 74 0.150000 -0.150000 -0.250000 0.0100000 + + 75 0.150000 -0.250000 0.250000 0.0100000 + + 76 0.150000 -0.250000 -0.250000 0.0100000 + + 77 0.150000 -0.350000 0.250000 0.0100000 + + 78 0.150000 -0.350000 -0.250000 0.0100000 + + 79 0.150000 -0.450000 0.250000 0.0100000 + + 80 0.150000 -0.450000 -0.250000 0.0100000 + + 81 0.050000 0.450000 0.250000 0.0100000 + + 82 0.050000 0.450000 -0.250000 0.0100000 + + 83 0.050000 0.350000 0.250000 0.0100000 + + 84 0.050000 0.350000 -0.250000 0.0100000 + + 85 0.050000 0.250000 0.250000 0.0100000 + + 86 0.050000 0.250000 -0.250000 0.0100000 + + 87 0.050000 0.150000 0.250000 0.0100000 + + 88 0.050000 0.150000 -0.250000 0.0100000 + + 89 0.050000 0.050000 0.250000 0.0100000 + + 90 0.050000 0.050000 -0.250000 0.0100000 + + 91 0.050000 -0.050000 0.250000 0.0100000 + + 92 0.050000 -0.050000 -0.250000 0.0100000 + + 93 0.050000 -0.150000 0.250000 0.0100000 + + 94 0.050000 -0.150000 -0.250000 0.0100000 + + 95 0.050000 -0.250000 0.250000 0.0100000 + + 96 0.050000 -0.250000 -0.250000 0.0100000 + + 97 0.050000 -0.350000 0.250000 0.0100000 + + 98 0.050000 -0.350000 -0.250000 0.0100000 + + 99 0.050000 -0.450000 0.250000 0.0100000 + + 100 0.050000 -0.450000 -0.250000 0.0100000 + +++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------- Symmetry and Constraints ------------------------------- There are no symmetry operations specified or generated for this cell There are no ionic constraints specified or generated for this cell Maximum deviation from symmetry = 0.00000 ANG Point group of crystal = 1: C1, 1, 1 Centre of mass is NOT constrained Number of cell constraints= 0 Cell constraints are: 1 2 3 4 5 6 External pressure/stress (GPa) 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 +---------------- MEMORY AND SCRATCH DISK ESTIMATES PER NODE -----------------+ | Memory Disk | | Model and support data 143.7 MB 0.0 MB | | Electronic energy minimisation requirements 34.4 MB 0.0 MB | | ----------------------------- | | Approx. total storage required per node 178.1 MB 0.0 MB | | | | Requirements will fluctuate during execution and may exceed these estimates | +-----------------------------------------------------------------------------+ ------------------------------------------------------------------------ <-- SCF SCF loop Energy Fermi Energy gain Timer <-- SCF energy per atom (sec) <-- SCF ------------------------------------------------------------------------ <-- SCF Initial -4.35639965E+003 5.53174845E+001 6.99 <-- SCF 1 -4.76035984E+003 4.02701031E+000 1.34653398E+002 26.41 <-- SCF 2 -4.80620916E+003 1.27051871E+000 1.52831048E+001 43.06 <-- SCF 3 -4.81000071E+003 8.33967813E-001 1.26385156E+000 63.51 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 4 -4.81211777E+003 2.97859038E-001 7.05685290E-001 87.49 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 5 -4.80787848E+003 1.05334557E+000 -1.41309548E+000 113.74 <-- SCF 6 -4.80789775E+003 1.15419165E+000 6.42439653E-003 138.87 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 7 -4.80764775E+003 1.24078933E+000 -8.33330734E-002 164.77 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 8 -4.80753133E+003 1.32226186E+000 -3.88070365E-002 190.10 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 9 -4.80749900E+003 1.42637498E+000 -1.07786426E-002 215.83 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 10 -4.80746509E+003 1.63112153E+000 -1.13015395E-002 240.09 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 11 -4.80744124E+003 1.78797744E+000 -7.95101041E-003 265.42 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 12 -4.80743149E+003 1.94496854E+000 -3.25054334E-003 287.17 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 13 -4.80743629E+003 2.02538023E+000 1.60177125E-003 309.40 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 14 -4.80744209E+003 2.04690285E+000 1.93145534E-003 333.51 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 15 -4.80744586E+003 2.06659130E+000 1.25889103E-003 357.45 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 16 -4.80744671E+003 2.06538821E+000 2.82305532E-004 381.73 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 17 -4.80744682E+003 2.07069792E+000 3.52137891E-005 403.09 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 18 -4.80744683E+003 2.06739867E+000 4.06057098E-006 423.17 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 19 -4.80744683E+003 2.06840906E+000 -1.27933557E-007 439.06 <-- SCF Warning: There are no empty bands for at least one kpoint and spin; this may slow the convergence and/or lead to an inaccurate groundstate. If this warning persists, you should consider increasing nextra_bands and/or reducing smearing_width in the param file. Recommend using nextra_bands of 7 to 16. 20 -4.80744683E+003 2.06828757E+000 1.41899508E-007 453.29 <-- SCF ------------------------------------------------------------------------ <-- SCF Final energy, E = -4807.405538452 eV Final free energy (E-TS) = -4807.446827965 eV (energies not corrected for finite basis set) NB est. 0K energy (E-0.5TS) = -4807.426183209 eV Writing model to Ti__0_0_1_.check *********************** Forces *********************** * * * Cartesian components (eV/A) * * -------------------------------------------------- * * x y z * * * * Ti 1 0.00477 -0.00828 0.00019 * * Ti 2 -0.00238 0.00415 0.38046 * * Ti 3 -0.00239 0.00413 -0.38065 * * * ****************************************************** Writing model to Ti__0_0_1_.check Writing analysis data to Ti__0_0_1_.castep_bin Initialisation time = 0.72 s Calculation time = 461.39 s Finalisation time = 0.37 s Total time = 462.48 s |
10楼2012-10-31 16:35:53
wzbhit
至尊木虫 (著名写手)
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2楼2012-10-30 23:43:59
3楼2012-10-31 09:32:22
wzbhit
至尊木虫 (著名写手)
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4楼2012-10-31 10:00:23