PAW IMPLEMENTATION IN ABINIT AND ATOMIC DATA GENERATION

Transcription

1 ABINIT Workshop, Uversty of Lege, Jauary 29-31, 2007 PAW IMPLEMENTATION IN ABINIT AND ATOMIC DATA GENERATION F. JOLLET, M. TORRENT, G.ZERAH, B. AMADON, F. BOTTIN, S. MAZEVET Commssarat à l'eerge Atomque, Cetre d'etudes de Bruyères le Châtel, Frace N. HOLZWARTH Wake Forest Uversty, Wsto-Salem, NC, USA X. GONZE Uversté Catholque de Louva-la-Neuve, Belgum ABINIT Workshop, Lège 30/01/2007 1

2 Summary PAW mplemetato ABINIT: State of the art PAW atomc data geerators for ABINIT ABINIT Workshop, Lège 30/01/2007 2

3 PAW mplemetato ABINIT- state of the art Wave fuctos: Ψ = Ψ + ( φ φ ) p Ψ = + - Hamltoa: H ψ = ε S ψ de 1 H = = + v + p D p d ρ eff, 2, Electroc desty Groud state propertes Eergy Forces Stresses P. Blöchl, Phys. Rev. B 50, (1994) ABINIT Workshop, Lège 30/01/2007 3

4 PAW mplemetato ABINIT- state of the art Iro equato of state: Cutoff covergecy A. Dewaele, P. Loubeyre, F. Ocell, M. Mezouar, P.I. Dorogokupets, M. Torret, PRL, 97, (2005) ABINIT Workshop, Lège 30/01/2007 4

5 E-E 0 (Ryd) PAW mplemetato ABINIT- state of the art PWPAW usg v v vs ABINIT usg ( ) H ZC No sgfcatve dfferece betwee results eve whe covergece ot reached E-E 0 (Ryd) FeO Cu (fcc) a (Å) a (Å) ABINIT Workshop, Lège 30/01/2007 5

6 PAW mplemetato ABINIT- state of the art New developmets: - GS parallelsato F. Bott talk - XML format for atomc data - LDA + U B. Amado talk - Waer fuctos - Electrcal coductvty S. Mazevet talk - Core level absorpto - Lear respose (phoos) M. Torret talk ABINIT Workshop, Lège 30/01/2007 6

7 PAW mplemetato ABINIT- state of the art How to develop a ew fuctoalty the PAW framework? Geeral way: apply the PAW trasformato to the formula you wat to code M = Ψ A Ψ = Ψ A Ψ wth A = A + p ( φ A φ φ A φ ) p, where A s a local operator Examples: Waer fuctos: A = e r r br Coductvty: A = Ψ Ψ m Lear respose ABINIT Workshop, Lège 30/01/2007 7

8 PAW mplemetato ABINIT- state of the art Approxmate way: case of localzed wavefuctos Whe the wavefucto Ψ s localzed the PAW sphere, the quatty M = Ψ A Ψ m f the partal wave bass s complete. I ths case, M s to be calculated oly the sphere, whch Ψ, p φ A φ p Ψ m Ψ = p Ψ φ Examples: Core level absorpto, LDA+U (localzed operator) The key quatty s: p It ca be calculated callg ctocpro.f90, outscfcv.f90 for stace Ψ You ca easly develop the PAW framework! ABINIT Workshop, Lège 30/01/2007 8

9 The PAW method APPROXIMATIONS : - Froze core approxmato - The partal wave bass s trucated - The plae wave bass s trucated ADVANTAGES : - Total desty of the system s computed o trasferablty problem - Plae wave cutoff equvalet to ultra-soft pseudopotetals (o orm-coservg costrat) - The PAW method s as précse as a all electro method. Covergecy ca be cotrolled. - It ca be show that ultrasoft ad orm-coservg methods are approxmatos of the PAW method. ATOMIC DATA: φ, φ, p, V,, We eed the followg atomc data: { } { }{ } H [ Zc ] c c ABINIT Workshop, Lège 30/01/2007 9

10 Buldg atomc data for PAW USPP Ultrasoft pseudopotetal geerator Wrtte by Davd Vaderblt Rutgers, The State Uversty of New Jersey Add a "plug" to USPP Oly have to use USPP to produce a fle for Abt Fully documeted by D. Vaderblt Set of put fles dowloadable o D. Vaderblt's ste Dowloadable o abt.org AtomPAW PAW atomc data geerator for "PWPAW" Wrtte by Natale Holzwarth ad coworkers Dept. of Physcs, Wake Forest Uversty Lauch AtomPAW ad a coverter separately Atompaw2abt.Fully documeted by M.Torret Dowloadable o abt.org New versos have bee updated ABINIT Workshop, Lège 30/01/

11 Buldg atomc data for PAW USPP ATOMPAW Step 1: Choose a radal grd Step 2: All electro atomc calculato Log Schrod., Scal. Rel. Log, l Schrod., Scal. Rel. Atomc Schrödger equato: c ae Choose a eergy set { } ad rad ad vert the Schrödger equato: Step 3: Pseudze the local potetal V ad V o r loc ae loc ε ( r), V ( r) { } r TM, polyom { φ (r)} TM, polyom, bessel Step 4: Choose a scheme to obta pseudowavefuctos ad proectors The Vaderblt scheme: φ ad φ o r polyom polyom, bessel 2 Get auxllary fuctos χ = [ + Vloc ε] ϕ Get proectors from auxllary fuctos by = ( ) 1 p B χ wth β = ϕ χ The Blöchl scheme: Choce of shape fucto k(r) Get prelmary pseudo fuctos by Get prelmary proectors by 2 0 [ + V ε C k( r) ] ϕ = 0 loc 0 2 p = + V loc ε 0 [ ] ϕ Gram-Schmdt orthogoalzato to get ϕ, p ABINIT Workshop, Lège 30/01/

12 Buldg atomc data for PAW USPP ATOMPAW Step 5: Pseudze the core desty c c ad o rcore Step 6: Compute v H [ Zc ] by uscreeg V loc v ( ) = v v ( + ˆ + ) v ( + ˆ + ) H ZC loc H Choose a shape fucto for ˆ c xc c polyom um polyom sc, gauss, bessel Atomc data valdato Accuracy Effcecy The PAW calculato must gve the same physcal results as a referece all electro calculato The plae wave bass must be as mmal as possble Good atomc data are always a compromse betwee accuracy ad effcecy ABINIT Workshop, Lège 30/01/

13 Buldg atomc data for PAW Nckel 28. GGA-PBE loggrd 1500 scalarrelatvstc potucleus ! Up to 4s, 4p ad 3d ! Electroc cofgurato 3d 9 4s 1 4p c! 1s c! 2s c! 3s v! 4s valece c! 2p c! 3p v! 4p valece v! 3d valece 2! Bass cotas s, p ad d partal-waves ! rpaw=2.3, rshape=2.3, rveff=1.1, rcore=2.2 y! Addtoal s partal-wave 4.! at Eref=4.0 Ha y! Addtoal p partal-wave 4.! at Eref=4.0 Ha y! Addtoal d partal-wave 2.5! at Eref=2.5 Ha custom rrk grahamschmdtortho sc! RRKJ PW + sc shape fuc. Bessel! Smple Bessel Vloc 2.3! Matchg radus for Ph1 (l=0) 2.3! Matchg radus for Ph2 (l=0) 2.3! Matchg radus for Ph3 (l=1) 2.3! Matchg radus for Ph4 (l=1) 2.3! Matchg radus for Ph5 (l=2) 2.3! Matchg radus for Ph6 (l=2) 0! END Iput fle for ATOMPAW ABINIT Workshop, Lège 30/01/

14 Buldg atomc data for PAW Parameters adustmet ca be tedous ABINIT Workshop, Lège 30/01/

15 Cocluso PAW atomc data geerato eeds a tral-error type of adustmet Each set of data must be tested the cotext of each Two types of atomc data ow avalable Abt s user ca dowload/geerate atomc data Fully documeted o Abt s web ste To be cotued Evaluate accuracy ad performace for elemets of the perodc table XML uversal format for PAW atomc data Sp orbt? ABINIT Workshop, Lège 30/01/