Dear QE users, Greetings!!!
I am trying to find the absorption spectrum for the material 'TiO2' supercell (2*1*1) which consists of 24 atoms. I tried a lot to find the absorption spectrum by reading all the related threads from QE. I have tried with all the methods such as turbo_davidson.x, turbo_lanczos.x and epsilon.x. I can only succeed with the use of epsilon.x but I am unable to get the same results for the turbo_davidson.x and turbo_lanczos.x. I would like to know the reason behind this. And secondly to find an absorption spectrum of the material does epsilon.x method gives accurate results when compared with the other two? Thirdly I have tried it for the Zn doped TiO2 supercell. This time all the methods did not give a hand for my calculation. The input files are given below. I would be very grateful if you help me out in this regard. Please let me know if you need any further information. Looking forward to hearing from you. Thanks in advance. # self-consistent calculation &control calculation = 'scf' prefix = 'TiO2' pseudo_dir = './' outdir = './outTiO2' !etot_conv_thr = 1e-5 forc_conv_thr = 1e-4 / &system ibrav = 0 celldm(1) = 14.113 nat = 24 ntyp = 2 ecutwfc = 80.0 ecutrho = 800 nbnd = 300 input_dft = 'pbe0' / &electrons mixing_beta=0.3 conv_thr = 1.0d-8 diagonalization = 'david', mixing_mode = 'plain', / &IONS / &cell / CELL_PARAMETERS (alat) 1.000927809 0.000000000 0.000000000 0.000000000 0.500440909 0.000000000 0.000000000 0.000000000 1.235414320 ATOMIC_SPECIES Ti 47.867 Ti.upf O 16.00 O.upf ATOMIC_POSITIONS (crystal) Ti 0.000000000 0.000000000 -0.000006420 Ti 0.500000000 0.000000000 -0.000006418 Ti 0.250000017 0.500000000 0.499993602 Ti 0.750000015 0.500000000 0.499993602 Ti 0.000000000 0.500000000 0.250006398 Ti 0.500000000 0.500000000 0.250006394 Ti 0.250000016 0.000000000 0.750006426 Ti 0.750000016 0.000000000 0.750006426 O 0.000000000 0.000000000 0.212511476 O 0.500000000 0.000000000 0.212511476 O 0.250000011 0.500000000 0.712511501 O 0.750000021 0.500000000 0.712511501 O 0.000000000 0.500000000 0.462514694 O 0.500000000 0.500000000 0.462514705 O 0.250000019 0.000000000 0.962514709 O 0.750000013 0.000000000 0.962514709 O 0.250000008 0.000000000 0.537488518 O 0.750000024 0.000000000 0.537488518 O 0.000000000 0.500000000 0.037488489 O 0.500000000 0.500000000 0.037488487 O 0.250000019 0.500000000 0.287485309 O 0.750000013 0.500000000 0.287485309 O 0.000000000 0.000000000 0.787485317 O 0.500000000 0.000000000 0.787485307 K_POINTS gamma # turbo_lanczos.x calculation &lr_input prefix ='TiO2' outdir ='./outTiO2' !restart_step = 100, !restart = .true. / &lr_control itermax = 500 ipol = 1 !d0psi_rs = .true. / # turbo_spectrum.x calculation &LR_INPUT prefix = 'TiO2' outdir = './outTiO2' itermax0 = 500 itermax = 10000 extrapolation = 'osc' epsil = 0.01 units = 1 start = 0.0 end = 4.0 increment = 0.01 ipol = 1 / # turbo_davidson.x calculation &lr_input prefix = 'TiO2' outdir = './outTiO2' / &lr_dav !if_dft_spectrum = .false. num_eign = 5 num_init = 10 num_basis_max = 90 residue_conv_thr = 1.0E-4 start = 0.0 finish = 3.50 step = 0.001 broadening = 0.004 reference = 0.3 / # turbo_spectrum.x calculation &lr_input prefix = 'TiO2' outdir = './outTiO2' td = 'davidson' epsil = 0.004 start = 0.0d0 end = 3.5d0 increment = 0.001d0 eign_file = 'TiO2.eigen' / Kind Regards, Vivek C __________________________________ Vivek Christhunathan PhD researcher Mechanical Engineering College of Engineering and Informatics Room 2053 Alice Perry Engineering Building National University of Ireland Galway Ireland E-mail: [email protected] Phone: +353 899811181, +91 9600752742
<<attachment: TiO2_supercell.zip>>
<<attachment: Zn_doped_TiO2_supercell.zip>>
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