From elias.assmann at gmail.com Tue Dec 1 12:36:16 2015 From: elias.assmann at gmail.com (Elias Assmann) Date: Tue, 01 Dec 2015 12:36:16 +0100 Subject: [Wannier] woptic: optical conductivity from Wien2k+many-body calculations Message-ID: <565D8630.1050002@gmail.com> Dear Wannier90 users! For those on the list who use Wien2k, I am happy to announce the release of *woptic* , a package to calculate the optical conductivity, dc conductivity, and thermopower in the Wien2k+Wannier90 ecosystem. Woptic builds upon the optic and wien2wannier modules of Wien2k, combined with Wannier90 and (optionally) an external many-body calculation, to work with the dipole matrix elements from optic in a basis of maximally-localized Wannier functions. Interesting features include: * woptic can incorporate a local self-energy ?(?) from a many-body calculation such as dynamical mean-field theory (DMFT) * it employs an adaptive k-integration scheme to sample the Brillouin zone efficiently * it uses the full dipole matrix elements, rotated to the Wannier basis * transitions beyond the Wannier orbitals can be included in an ?outer window?. For more information, and to download the code, visit . Since the code is still new, feedback is especially welcome, either through the GitHub page , or by e-mail. For the theory behind woptic and a description of the algorithm see the preprint woptic: optical conductivity with Wannier functions and adaptive k-mesh refinement E. Assmann, P. Wissgott, J. Kune?, A. Toschi, P. Blaha, K. Held Note: Long-time users of wien2wannier may know woptic as a part of early releases of that package. Since then, it has been much expanded and updated to work with the current version of wien2wannier. Elias Assmann for the woptic authors -- Elias Assmann Institute of Theoretical and Computational Physics TU Graz ?https://itp.tugraz.at/? From suresh2007pgp19 at gmail.com Wed Dec 2 14:47:32 2015 From: suresh2007pgp19 at gmail.com (Suresh A) Date: Wed, 2 Dec 2015 19:17:32 +0530 Subject: [Wannier] Computing Figure of Merit:Reply Message-ID: Respected Sir, As per your advice I go through the Boltzwann paper to compute seebeck coefficient. The following is my understanding Seebeck coefficient = integration of {g(epsilon) x f(epsilon)} Dos file contains Energy versus Number of states. And in fermi dirac distribution function we have {epsilon - epsilon(f)}. Where epsilon can be taken from DOS where it has lots of energy values from valence band to conduction band and fermi energy can be taken from pwscf band structure calculation.Then doing calculation for all energy values in dos and addition of these values gives chemical potential at a given temperature. >From this one can find out seebeck coefficients. Is my understanding is correct sir? If it is right finding out electrical conductivity and thermal conductivity at given temperature can also be findout. So one can findout electronic part of ZT. Thanks in advance. With Regards, A.Suresh, Research Scholar, Madurai Kamaraj University, Madurai. -------------- next part -------------- An HTML attachment was scrubbed... URL: From pike.lucius at gmail.com Thu Dec 17 15:31:39 2015 From: pike.lucius at gmail.com (Tobias Frank) Date: Thu, 17 Dec 2015 15:31:39 +0100 Subject: [Wannier] Initial projection wannier centers (symmetry adapted wannier functions) Message-ID: Dear wannier90 users, I currently try to wannierize MoS2, which has a disconnected band manifold of 11 bands (5 Mo d orbitals and 2*3 S p orbitals). *----------------------------------------------------------------------------* | Site Fractional Coordinate Cartesian Coordinate (Ang) | +----------------------------------------------------------------------------+ | Mo 1 0.33333 0.66667 0.50000 | -0.00000 1.84059 12.50000 | | S 1 0.66667 0.33333 0.56240 | 1.59400 0.92030 14.05992 | | S 2 0.66667 0.33333 0.43760 | 1.59400 0.92030 10.94008 | *----------------------------------------------------------------------------* The goal is to get a symmetric tight-binding Hamiltonian (_hr.dat) out of the calculation. The scheme I use is to project onto atomic orbitals without any maximal localization iteration applied ("symmetry adapted wannier functions") and guiding centers are turned on. My initial (and final) state reads: projections:Mo:d, S:p Initial State WF centre and spread 1 ( -0.000000, 1.840629, 12.500000 ) 1.65212451 WF centre and spread 2 ( -0.000000, 1.797275, 12.500000 ) 1.88788741 WF centre and spread 3 ( -0.000000, 1.883825, 12.500000 ) 1.88514896 WF centre and spread 4 ( -0.000000, 1.744405, 12.500000 ) 1.79754077 WF centre and spread 5 ( -0.000000, 1.936664, 12.500000 ) 1.79758431 WF centre and spread 6 ( 1.594000, 0.920313, 14.121223 ) 1.69614206 WF centre and spread 7 ( 1.594000, 0.932663, 14.015563 ) 1.56344882 WF centre and spread 8 ( 1.594000, 0.908001, 14.015556 ) 1.56201127 WF centre and spread 9 ( 1.594000, 0.920313, 10.878777 ) 1.69614206 WF centre and spread 10 ( 1.594000, 0.932663, 10.984437 ) 1.56344882 WF centre and spread 11 ( 1.594000, 0.908001, 10.984444 ) 1.56201127 Sum of centres and spreads ( 9.564000, 14.724751,137.500000 ) 18.66349025 This yields a very good description of the band structure, but why are the initial projections not exactly at the atomic sites, where I specified them to be? This slight asymmetry reflects also in the tight-binding matrix elements, where I would like to have symmetric ones. Could you give me a hint how to get the wannier centers at the atomic positions? I am aware about the publication of Sakuma ("Symmetry-adapted Wannier functions in the maximal localization procedure"). I am using Quantum Espresso, where it is not implemented. Is there any work on the way? Thank you very much, Tobias Frank PhD student Universit?t Regensburg -------------- next part -------------- An HTML attachment was scrubbed... URL: