Dear QE users. Our group started to use QE and tries to combine the code with a global structural search routine. For this purpose valence only pseudopotentials (PP) optimized for a low energy cutoff has to be used (at the cost of computational correcetness of course). As a test case we want to start with Bi. For this element only a relatively hard PP exists which incoperates a d semicore state. Since the converted FHI PP 5-electron PPs does not work very well I decided to try to create a own PP.
Have done the tutorial for Si and the example calculation for Ti and everything seemed to work all right. Because I am not very familiar with the theory of the PP fitting routines I tried to progress for Bi in the same manner as for Si and Ti. So I started with: &input iswitch=3, rlderiv=2.20, eminld=-2.0,emaxld=1.0,deld=0.01d0,nld=3, rel=1,zed=83.0,config="[Xe] 4f14 5d10 6s2 6p3 6d-1",dft='PBE', / &inputp lloc=2,pseudotype=1,file_pseudopw='Bi.pbe-n-rrkj.UPF', zval=5.0,rho0=0.01 / 3 6S 1 0 2.00 0.00 2.20 2.20 6P 2 1 3.00 0.00 2.20 2.20 6D 3 2 0.00 -0.10 2.20 2.20 But unfourtunately this input file produces the error "phi has nodes before r_c". Therefore tried to change rho0 , rcore and rcut systematically without success. Therefore used tm=.true. which produced a PP which looked good. Depressingly the TM potential failed to converge for test calculations for the dimer. Therefore changed the following things in the input: config="[Xe] 4f14 5d10 6s2 6p3", lloc=1, and got rid of the 6D in the PP card. In this way I am able to generate a PP. The wavefunctions and the logDev look ok. But the performance for the Dimer is not really good (40 Ry Ecutoff, RhoCutoff= 8*Ecutoff) -> 2.52 AA bondlength compared to 2.66 AA experimentally. For example a Lanl2DZ calculation in NWChem with the same functional yields 2.64 AA. Additionally any influence of the 6D state is not descibed with the potential. Every time I want to change the settings for the PP the program produces an error. I am not able so far to write in the 6D channel or in two channels (pseudotype=2) or to generate a US-PP (pseudotype=3). Since I am far away from beeing an expert and this are only my first attempts I wondered if someone has any suggestions what I could try to improve the PP for Bi step by step. Best wishes Sven -- Dipl. Ing. Sven Heiles Technische Universit?t Darmstadt AK Sch?fer Eduard-Zintl-Institut Petersenstra?e 20 D-64287 Darmstadt ? Germany Phone: ++49-(0)6151-164397 Fax: ++49-(0)6151-166024 Web: http://www.tu-darmstadt.de/fb/ch/cluster/schaefer.tud
