Dear sir, As per my understanding, the reciprocal lattice vectors (A,B,C) in 3D are defined as A=(2pi bxc)/(a (bxc)) where, a,b,c represent real space vectors with x marking cross product.
Hence for a set of a,b,c vectors perpendicular to each other in the positive real space, the reciprocal lattice vector A would fall along the same direction as the real space vector a. If so, the specification of my k points for the band structure calculation lie along the first lattice direction whereas my requirement is in the third dimension (completely my fault). However, I do not understand your statement that my s*election of k points are along a diagonal line of the 1st and 3rd lattice vectors*. Can you please clarify regarding this and help me understand the fault. Thank you On Tue, 31 Aug 2021 at 06:39, Pasan Henadeera <henadeer...@gmail.com> wrote: > Hi, thank you for the reply. > 1. I tried with and without fractional coordinates and the results were > similar. > 2. The atomic mass was specified because I wanted to make sure that the > problem was not caused due to that. > 3. Yes, the k points could be a source of the problem. > 4. I tried both SZ and DZ and there was not much variation in the results. > I shall try using SZP and DZP as well. > > I shall work on your suggestions and let you know what happens. Thanks for > the assistance. > > > Thank you > > On Tue, 31 Aug 2021 at 01:30, Nick Papior <nickpap...@gmail.com> wrote: > >> Hi, >> >> A couple of notes on the input. Why are you using fractional coordinates >> for such a system, it seems a bit weird to me. But ok, the system looks ok. >> >> You don't need to use the AtomicMass block in case you want to use the >> default mass of Si (which if I recall is 28.09). >> >> Your k-point input indicates to me that you don't understand what it >> does? The k-points you have selected are along a diagonal line of the 1st >> and 3rd lattice vector. You probably only want along the 3rd? Please >> carefully go through your input options and what they mean. >> >> Lastly, did you try and converge the basis set? Using only SZ might not >> be good enough here. >> >> Den søn. 29. aug. 2021 kl. 22.00 skrev Pasan Henadeera < >> henadeer...@gmail.com>: >> >>> Hello Siesta users, >>> I am trying to evaluate the band gap variation in Si nanowires (without >>> any passivation). However, I have been unable to obtain a reasonable band >>> structure comparable to available literature ( >>> https://doi.org/10.1016/j.physe.2005.12.094). >>> >>> Any ideas or suggestions? >>> >>> >>> SystemName Si >>> SystemLabel Si >>> >>> NumberOfSpecies 1 >>> NumberOfAtoms 57 >>> >>> %block ChemicalSpeciesLabel >>> 1 14 Si >>> %endblock ChemicalSpeciesLabel >>> >>> %block AtomicMass >>> 1 28 >>> %endblock AtomicMass >>> >>> LatticeConstant 5.3162811000 Ang >>> >>> %block LatticeVectors >>> 0.0000000000 17.0000000000 0.0000000000 >>> 0.0000000000 0.0000000000 17.0000000000 >>> 1.0000000000 0.0000000000 0.0000000000 >>> %endblock LatticeVectors >>> >>> >>> AtomicCoordinatesFormat Fractional >>> %block AtomicCoordinatesAndAtomicSpecies >>> 0.4218750001 0.4531250001 0.7500000009 1 >>> 0.4218750001 0.4843750001 0.2500000009 1 >>> 0.4208485475 0.5157487486 0.7512270222 1 >>> 0.4205211402 0.5462557586 0.2323127590 1 >>> 0.4842479144 0.4208701616 0.2481823356 1 >>> 0.4537269539 0.4205721769 0.7671556118 1 >>> 0.4386097200 0.4385553039 0.9829884767 1 >>> 0.4689609805 0.4376984553 0.5053350471 1 >>> 0.4688488746 0.4688446650 0.0003473838 1 >>> 0.4381741853 0.4690624505 0.5037780301 1 >>> 0.4533432439 0.4532006119 0.2542710091 1 >>> 0.4844977098 0.4534676431 0.7520747802 1 >>> 0.4843956661 0.4844028848 0.2508846043 1 >>> 0.4535760099 0.4845509954 0.7526387478 1 >>> 0.4379725900 0.5001831894 0.9964957459 1 >>> 0.4689187754 0.5000018849 0.4997524134 1 >>> 0.4688466704 0.5311626528 0.9994608317 1 >>> 0.4376911579 0.5310443690 0.4943530582 1 >>> 0.4535076989 0.5155265650 0.2484398088 1 >>> 0.4843981130 0.5156022583 0.7489904851 1 >>> 0.4845031869 0.5465300316 0.2479006330 1 >>> 0.4532537185 0.5467402717 0.7445710047 1 >>> 0.4386536374 0.5613490668 0.0209871088 1 >>> 0.4689504767 0.5623096662 0.4943742384 1 >>> 0.4537407911 0.5794778627 0.2321660756 1 >>> 0.4842634606 0.5791191600 0.7515145823 1 >>> 0.5462628443 0.4205258128 0.2322107930 1 >>> 0.5157447994 0.4208750213 0.7517376987 1 >>> 0.4999969254 0.4377903480 0.9998958351 1 >>> 0.5310470849 0.4376968379 0.4943589947 1 >>> 0.5311609069 0.4688409117 0.9995670075 1 >>> 0.4999982405 0.4689091066 0.4999235161 1 >>> 0.5154961788 0.4534701711 0.2478658343 1 >>> 0.5467429914 0.4532536631 0.7446390767 1 >>> 0.5465316338 0.4845048549 0.2478709280 1 >>> 0.5155991333 0.4843974423 0.7490231357 1 >>> 0.5000012391 0.5000012294 0.9999860448 1 >>> 0.5310933384 0.5000012038 0.4999818520 1 >>> 0.5311584743 0.5311590261 0.0003877805 1 >>> 0.5000006752 0.5310898094 0.4999793991 1 >>> 0.5155993795 0.5156016028 0.2509924240 1 >>> 0.5465322721 0.5154974225 0.7521165594 1 >>> 0.5467453831 0.5467413239 0.2554397791 1 >>> 0.5154934165 0.5465280455 0.7521133862 1 >>> 0.5000025233 0.5622200175 0.9999154108 1 >>> 0.5310541581 0.5623080249 0.5055918525 1 >>> 0.5157243943 0.5791157145 0.2486224609 1 >>> 0.5462587742 0.5794774930 0.7678772422 1 >>> 0.5613462417 0.4386515218 0.0210208787 1 >>> 0.5623109375 0.4689459928 0.4943827650 1 >>> 0.5794716486 0.4537426560 0.2321699186 1 >>> 0.5791173816 0.4842648445 0.7515189669 1 >>> 0.5622181911 0.5000006977 0.0000456673 1 >>> 0.5623061750 0.5310497879 0.5056290910 1 >>> 0.5791238231 0.5157378818 0.2484404107 1 >>> 0.5794790635 0.5462573038 0.7678478138 1 >>> 0.5613422586 0.5613429826 0.9788443617 1 >>> %endblock AtomicCoordinatesAndAtomicSpecies >>> >>> %block kgrid_Monkhorst_Pack >>> 0 1 0 0.5 >>> 0 0 1 0.5 >>> 32 0 0 0.5 >>> %endblock kgrid_Monkhorst_Pack >>> >>> XC.functional LDA >>> XC.authors CA >>> SpinPolarized .false. >>> MeshCutoff 300 Ry >>> kgrid_cutoff 100.0 Ang >>> >>> PAO.BasisSize SZ >>> >>> MD.TypeOfRun CG >>> MD.VariableCell true >>> MD.NumCGsteps 500 >>> MD.MaxCGDispl 0.1 Bohr >>> MD.MaxForceTol 0.1 eV/Ang >>> MD.MaxStressTol 0.001 eV/Ang**3 >>> %block GeometryConstraints >>> position 1 2 >>> stress 4 5 6 >>> %endblock GeometryConstraints >>> >>> MD.UseSaveXV true >>> >>> MaxSCFIterations 500 >>> DM.MixingWeight 0.01 >>> DM.NumberPulay 3 >>> DM.Tolerance 1.d-3 >>> ElectronicTemperature 25 meV >>> SolutionMethod diagon >>> >>> BandLinesScale pi/a >>> %block BandLines >>> 1 -0.590938025 0.0000000000 0.0000000000 Y # -Y >>> 50 0.0000000000 0.0000000000 0.0000000000 \Gamma >>> 50 0.590938025 -0.0000000000 -0.0000000000 Y >>> %endblock BandLines >>> >>> >>> >>> Thank you >>> -- >>> Best regards >>> Pasan Henadeera >>> >>> -- >>> SIESTA is supported by the Spanish Research Agency (AEI) and by the >>> European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) >>> >> >> >> -- >> Kind regards Nick >> >> -- >> SIESTA is supported by the Spanish Research Agency (AEI) and by the >> European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) >> > > > -- > Best regards > Pasan Henadeera > -- Best regards Pasan Henadeera
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
