Thanks to all who replied. Additional comments follow: 1) Negative occupations. I should have guessed...or scanned INPUT_LD1 more thoroughly. Let me see if I got this right. In constructing a PP for sulfur, I should "unoccupy" the 3d states? But what about heavily oxidized sulfur molecules, like in SF6 where S3d participates in the bonding? I guess this is why PP cooking requires a good chef.
2) TM PP examples. This was, as we Yanks say, a purposely "loaded question." Or casting a net seeking pearls of wisdom. Those following my LDA+U thread know I'm looking for a Cu PP (and probably an O partner) that will yield a gap in cuprate compounds (nominally divalent Cu-O bonds). I strongly suspect given the notoriety of this family of structures, many have tried and failed. The only formalism that I know which has succeeded in this endeavor has been LDA+U on an LMTO basis set. The Cu PP issue may perhaps be the most interesting challenge facing PP "theory and practice" today. Thanks for pointing out that the CVS /pseudo_library/... does contain some TM examples, but they're 4d and 5d. As far as I know, none of their monoxides are Hubbard insulators (if indeed they can be formed chemically at all...during the pandemonium of early Spring, 1987, my group at IBM Almaden mined the whole 4 and 5 series searching for HTSCs with no hits. Those were very heady and na?ve days.). 2a) I'm going to try to "reverse engineer" Fe.pz-nd-rrkjus.UPF used in example 25 into an ".in" file (does anyone have one?) to try and understand better how ld1.x works (an O.pz-rrkjus.in file already exists in /atomic_doc/pseudo_library/LDA/SR, but the O.pz-rrkjus.UPF produced by CVS ld1.x is "somewhat" different than that contained in the distro library /pseudo and used in example 25 (different total energies by a few tenths of a percent, no E pseu and no wfc and rho suggested cutoffs in the latter and fewer mesh points in the former ???)). Simplistically, Fe++ is the minority spin electron analog of the minority spin hole state expected in Cu++. 3) ld1.x - CVS vs Espresso. Espresso ld1.x screws up the &input namelist sequence, especially the "author" entry (is "ADC" the mysterious Andrea Dal Corso?), and about half the time fails to properly format the total energy (all asterisks in the UPF output, likely a Fortran format placeholder limit problem). 4) Grace output. Another loaded question. I anticipated Paolo's answer, but was hoping that some saintly soul in a state of grace...usually a postdoc...in the PWscf community had taken this task on. Paul M. Grant, PhD Principal, W2AGZ Technologies Visiting Scholar, Applied Physics, Stanford University EPRI Science Fellow (Retired) IBM Research Staff Member Emeritus w2agz at pacbell.net http://www.w2agz.com ? ? -----Original Message----- From: pw_forum-bounces at pwscf.org [mailto:[email protected]] On Behalf Of Lorenzo Paulatto Sent: Friday, January 18, 2008 1:28 AM To: pw_forum at pwscf.org Subject: Re: [Pw_forum] ld1.x Questions On Thu, January 17, 2008 22:20, Paul M. Grant wrote: > 1) What is the purpose of the "negative ocs(nl)" settings one sees > frequently in the input files in /atomic_doc/pseudo_library? (not covered > that I can see in INPUT_LD1) It doesn't seem to make physical sense. Orbitals with negative occupation are excluded from the all-electron calculation; you need to do this when they are unbounded. Putting a negative occupation means: I don't really want to compute this orbital, but I'd like to use it's label later for a specific orbital identified by an arbitrary, but well defined, reference energy, and L and M indexes. There is probably a more formal way to say that. > 2) Why doesn't this library contain some transition metal examples? The examples in the library are the pseudopotentials that Andrea Dal Corso (and only he) has done during the years. There are a few transition metals among them in the CVS version. > 3) I've observed ld1.x from O-sesame (CVS) performs much better the > executable in the present distribution espresso-3.2.3, which yields a > number of formatting errors. There have been a few improvements on that front recently, nothing should really change but the number of things that can will cause crashes has been reduced a bit. Keep in mind that "input files which produce a good pseudo" are a tiny subset of "input files which doesn't cause a crash." > 4) It's stated that ld1.x output can be plotted with Grace, but I see > no options to produce or launch .agr files such as exists in Opium. I > guess it has to be done "by hand." I think you are right. > -Paul -- Lorenzo Paulatto SISSA & DEMOCRITOS (Trieste) +39 040 3787 511 http://people.sissa.it/~paulatto/ ---------------------------------------------------------------- SISSA Webmail https://webmail.sissa.it/ Powered by SquirrelMail http://www.squirrelmail.org/ _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum
