The present file contains informations about the complete set of pseudopotentials generated by D.C. Allan and A. Khein, available on the ABINIT Web site. These pseudopotentials are single projector, ordinary norm conserving, based on the Troullier-Martins method. All these pseudopotentials have been tested against ghost states. Their cut-off radii follows reasonable trends across the periodic table. Some of them have been the subject of systematic testing. Many others have been used since the release of this table, during 1995, as this set has been provided with the plane_wave code commercialized by Biosym (BiosymII), before being used in connection with ABINIT. This file present a list of results obtained with these pseudopotentials, and provide some comparison with LAPW and experimental results. Comparison with LAPW is meaningful, as the LDA is common to both, and the convergence parameters have been chosen identical when possible. WARNING : The comparison with experimental results is NOT indicative of the accuracy of the pseudopotential for numerical work, since it will depend first on the accuracy of the LDA, and second, on the numerical parameters of the tests, in particular the number of k points: in most cases this was NOT lead to full convergence. Experimental data (often without ref !) are provided to discuss potential problems with the pseudopotentials or numerical convergence. In these tests, one will compare lattice constant - acell (bohr) - and bulk modulus - b0 (hartree/bohr^3, with 1 hartree/bohr^3 = 29421.033 GPa). The cut-off energy - ecut (Hartree) is an important parameter for planewave basis convergence, and the behaviour of acell and b0 is provided as a function of ecut. Thus, the practical information that one can gain from the present data are: - an estimation of the cut-off energy to be used to start convergence studies for other materials, with these pseudopotentials - some warnings about the importance of semi-core states : some pseudopotentials are inappropriate for use in a strongly electronegative environment, for example in bonds with Oxygen atoms (!) There are 20 crystals represented below (in alphabetical order) : BaTiO3, C, CeO2, CuBr, GaAs, Ge, InSb, KCl, KI, KNbO3, LiF, MgS, NaCl, PbZrO3, RbI, Si, TlCl, Yb, ZnS, and ZnSe. Thus, this file provides information on the pseudopotentials for the following 27 elements : As, Ba, Br, C, Ce, Cl, Cu, F, Ga, Ge, I, In, K, Li, Mg, Na, Nb, O, Pb, Rb, S, Sb, Se, Si, Ti, Tl, Zn. For each crystal, one finds first the result (acell, b0) using the present pseudopotential table (0), then experimental data (1), then lapw (2), then eventual other relevant data. Then some additional information : the numerical parameters of the present calculation, or bibliographical infos. Then a convergence study, then some comments. **************************************** BaTiO3 acell b0 (0) 7.90583 .02229689 Present, 10 sp, ecut=35 (1) 7.5778 Exp. (2) 7.45 lapw (from King-Smith+Vanderbilt PRB 49, 5828 (1994)) Convergence of (0) ecut acell Etot d2edx2 b0 b0' 35 7.90583 -71.75573246 .39661955 .02229689 4.61792795 NOTE : the bad lattice parameter wrt experiment can be attributed to the lack of semi-core 3s and 3p state for the Titanium pseudopotential. Semicore states are important in this case, because the strongly electronegative oxygen pump the electrons of Ti ... **************************************** C acell b0 (0) 6.69171 .015498 Present, 2sp, ecut=50 (1) 6.741 .01502 Exp Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 6.76518 -11.83805645 .25577589 .01680343 7.65504363 15 6.72330 -11.99928675 .18756893 .01239927 4.76660316 20 6.70916 -12.06037543 .23429604 .01552082 3.64182667 25 6.69190 -12.07143817 .23520357 .01562110 3.64991544 30 6.69246 -12.07299436 .23333254 .01549555 3.64052864 35 6.69251 -12.07331477 .23335813 .01549713 3.63707511 40 6.69194 -12.07359373 .23347528 .01550623 3.64308353 45 6.69174 -12.07379469 .23333287 .01549724 3.64019181 50 6.69171 -12.07392088 .23334942 .01549841 3.63946513 **************************************** CeO2 acell b0 (0) 12.02537 .00250819 Present, 2 sp, ecut=35 (1) 10.225 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 20 11.37152 -36.29574319 .18407408 .00719435 2.97906597 25 12.18576 -36.50506602 .05591076 .00203920 4.21893854 30 12.01906 -36.53740553 .06858205 .00253605 4.09821618 35 12.02537 -36.54430893 .06786434 .00250819 4.11053753 NOTE : the bad lattice parameter wrt to experiment could come from a too soft pseudopotential, or a lack of k points, or even from the LDA ! **************************************** CuBr acell b0 (0) 10.44645 .00211778 Present, 10 sp, ecut=40 (1) 10.75 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 20 10.31035 -67.77801084 .05189193 .00223689 4.68626483 25 10.40127 -68.96085814 .05154285 .00220242 5.41383681 30 10.43451 -69.23610234 .05035934 .00214499 5.40905077 35 10.44565 -69.28622321 .04969485 .00211443 5.32420911 40 10.44645 -69.29245307 .04977741 .00211778 5.32823650 NOTE : the 3d electrons of Cu demand a high ecut. **************************************** GaAs acell b0 (0) 10.32069 .00281133 Present, 2 sp, ecut=10 (1a)10.662 .00266 Exp., see Nielsen & Martin, Phys. Rev. B 32, 3792 (1985). (1b)10.683 .00268 Exp., see Ihm & Joannopoulos, Phys. Rev. B 24, 4191 (1981). (2) 10.63525 .00242491 lapw, 2 sp (Alex Khein) (3) 10.31637 .00280981 Other TM pseudopotential, 2 sp, ecut=30 Convergence of (3) ecut acell Etot d2edx2 b0 b0' 05 10.32849 -10.72338064 .06144027 .00264383 4.16068683 10 10.32068 -10.73655972 .06528396 .00281135 4.59015040 20 10.31663 -10.73997682 .06523807 .00281048 4.62708169 30 10.31637 -10.74010831 .06522073 .00280981 4.62679512 Convergence of (0) is same as that of (3). ecut acell Etot d2edx2 b0 b0' 10 10.32069 -10.73683231 .06528346 .00281133 4.59013355 **************************************** Ge acell b0 (0) 10.45124 .00264655 Present, 10 sp, ecut=40. (1a)10.681 .00262 Exp., see Yin and Cohen, Phys. Rev. B 26, 5668 (1982). (1b)10.677 .00261 Exp., see Nielsen & Martin, Phys. Rev. B 32, 3792 (1985). Convergence of (0) ecut acell Etot d2edx2 b0 b0' 05 10.42147 -10.06921548 .06120818 .00261034 4.95801315 10 10.44798 -10.10946927 .06331623 .00269339 4.63888046 15 10.44766 -10.11513681 .06262526 .00266409 4.70669933 20 10.45100 -10.11694086 .06223257 .00264653 4.67345001 30 10.45121 -10.11724831 .06224021 .00264681 4.67049786 40 10.45124 -10.11732594 .06223447 .00264655 4.67182070 **************************************** InSb acell b0 (0) 11.57070 .00190571 Present, 10 sp, ecut=25 (1) 12.243 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 5 11.61529 -10.03348129 .04569867 .00174860 4.58884406 10 11.57566 -10.05720398 .05080794 .00195076 5.07212776 15 11.57075 -10.06415054 .04960653 .00190544 4.98618778 20 11.57081 -10.06459277 .04957256 .00190412 4.97977831 25 11.57070 -10.06490900 .04961350 .00190571 4.98595553 NOTE : semicore 4d states might be needed for In. **************************************** KCl acell b0 (0) 12.07417 .00068937 Present, 2 sp, ecut=30. (1a)11.89 .000670 Exp. (1b)11.79 Exp. (2) 11.56660 .00082554 lapw, 2 sp (Alex Khein) Convergence of (0) ecut acell Etot d2edx2 b0 b0' 30 12.07417 -33.84009477 .01872814 .00068937 5.07275107 **************************************** KI acell b0 (0) 13.41731 .00046229 Present, 2 sp, ecut=30. (1) 13.36 .000398 Exp. (2) 12.91145 .00054908 lapw, 2 sp (Alex Khein) Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 13.53076 -31.57524273 .01424581 .00046793 4.30704897 15 13.43027 -31.61368086 .01385196 .00045840 4.92372641 20 13.41736 -31.61665632 .01395020 .00046209 5.01409895 25 13.41748 -31.61721674 .01396052 .00046243 5.00743101 30 13.41731 -31.61767432 .01395610 .00046229 5.00902509 **************************************** KNbO3 acell b0 (0) 8.03339 .02175020 Present, 10 sp, ecut=30 (1) 7.58 Exp. (from King-Smith+Vanderbilt PRB 49, 5828 (1994)) (2) 7.488 lapw (from King-Smith+Vanderbilt PRB 49, 5828 (1994)) Convergence of (0) ecut acell Etot d2edx2 b0 b0' 20 8.04244 -73.18829985 .41473429 .02291921 4.05925771 25 8.04202 -73.42412542 .38551325 .02130550 4.27473026 30 8.03339 -73.48444944 .39313748 .02175020 4.24896923 NOTE : semicore states might be needed for the Nb pseudopotential in the presence of electronegative oxygen. **************************************** LiF acell b0 (0) 7.70575 .00276340 Present, 10 sp, ecut=40 (1) 7.597 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 15 7.73441 -24.33099404 .05014266 .00288136 6.16938411 20 7.80452 -24.87218438 .06540478 .00372461 2.35027217 25 7.74858 -25.10005721 .04259643 .00244325 3.93631029 30 7.71322 -25.18066480 .04903335 .00282536 4.07016856 35 7.70682 -25.20271478 .04790631 .00276271 4.16814366 40 7.70575 -25.20691894 .04791162 .00276340 4.21731835 NOTE : the 2p electrons of Fluorine demand a high cut-off energy. **************************************** MgS acell b0 (0) 9.73912 .00283529 Present, 10 sp, ecut=20 (1) 9.8266 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 9.74238 -12.38271718 .06193946 .00282566 4.14005348 15 9.73865 -12.38619663 .06219016 .00283818 4.11473786 20 9.73912 -12.38815996 .06212977 .00283529 4.09445283 **************************************** NaCl acell b0 (0) 10.47177 .00117877 Present, 2 sp, ecut=20 (1a)10.582 .000904 Exp. (1b)10.658 Exp. (2) 10.44243 .00105384 lapw, 2 sp (Alex Khein) Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 10.47416 -22.98001420 .02765559 .00117349 5.27012543 20 10.47177 -22.99094114 .02777356 .00117877 5.19754969 **************************************** PbZrO3 acell b0 (0) 8.34436 .01874107 Present, 10 sp, ecut=30 (1) 7.7668 Exp. NOTE : semicore states are definitely needed for Pb as well as Zr, see the comment on BaTiO3. **************************************** RbI acell b0 (0) 13.95057 .00042382 Present, 10 sp, ecut=20 (1) 13.871 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 13.95143 -30.03817339 .01330642 .00042390 5.16176399 15 13.95080 -30.04863071 .01331246 .00042411 5.14966285 20 13.95057 -30.05128579 .01330325 .00042382 5.14618128 **************************************** Si acell b0 (0) 10.21572 .00320012 Present, 2sp, ecut=20. (1a)10.259 .00336 Exp., see Yin and Cohen, Phys. Rev. B 26, 5668 (1982). (1b)10.263 .00337 Exp., see Nielsen & Martin, Phys. Rev. B 32, 3792 (1985). Convergence of (0) ecut acell Etot d2edx2 b0 b0' 5 10.28812 -8.84901608 .07113187 .00307288 3.96857170 10 10.21457 -8.86725003 .07373241 .00320816 4.22989617 15 10.21547 -8.86984610 .07356532 .00320060 4.20822798 20 10.21572 -8.87029473 .07355601 .00320012 4.20750185 **************************************** TlCl acell b0 (0) 7.71721 .00385530 Present, 10 sp, ecut=30 (1) 7.2314 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 10 7.72014 -18.64741166 .06704874 .00385996 4.29268140 15 7.71898 -18.65955033 .06700461 .00385800 4.27495739 20 7.71787 -18.66217719 .06709814 .00386394 4.26516400 25 7.71734 -18.66458783 .06693242 .00385466 4.27668788 30 7.71721 -18.66531958 .06694247 .00385530 4.27578066 NOTE : the error in the cell parameter is to be attributed to the lack of semicore states. **************************************** Yb acell b0 (0) 9.95275 .00052866 Present, 2 sp, ecut=40 (1) 10.358 Exp. Convergence of (0) ecut acell Etot d2edx2 b0 b0' 35 9.95726 -84.41873943 .01168913 .00052175 1.85748564 40 9.95275 -84.42082730 .01183857 .00052866 2.01091840 NOTE : the error on the lattice parameter might be due to the very inaccurate k-point sampling, since Yb is a metal... **************************************** ZnS acell b0 (0) 10.07018 .00286110 Present, 2 sp, ecut=50. (1) 10.2123 .00261 Exp. (ref. in Martins et al PRB 43, 2213 (1991)). (2a)10.1157 .00296 lapw (Martins et al PRB 43, 2213 (1991)). (2b)10.02671 .00293672 lapw, 10 sp, Alex Khein Convergence of (0) ecut acell Etot d2edx2 b0 b0' 30 10.07122 -72.61951511 .06478546 .00285899 4.39154224 40 10.07014 -72.62231669 .06485548 .00286239 4.42473262 50 10.07018 -72.62410724 .06482658 .00286110 4.42808050 NOTE : the 3d electrons of Zn require a high cut-off energy **************************************** ZnSe acell b0 (0) 10.55093 .00236365 Present, 2 sp, ecut=60 (1a)10.677 Exp. (Kittel) (1b)10.709 Exp. (Pankove) (1c)10.711 Exp. (Wang and Klein after correction) Convergence of (0) (e99.0=19.7, e99.9=25.1 (Zn(3d))) 30 10.55014 -72.62842490 .05611463 .00236393 4.56988631 40 10.55091 -72.63123392 .05608830 .00236265 4.58916452 50 10.55092 -72.63302367 .05612227 .00236408 4.59065156 60 10.55093 -72.63346840 .05611220 .00236365 4.58993535 NOTE: the 3d electrons of Zn require a high cut-off energy