Dear Axel, So you say you used ld1.x to generate both UPF and cpmd pseudopotentials, or did you use another software? In INPUT_LD1.txt they say this is still an "experimental feature"...
Which software would you recommend to generate both pseudopotentials consistently? I must admit I am not very confident with using ld1, but if it does the job I should be able to handle it (with a little bit of help probably...) . Another question: I have a very simple case, the O pseudopotential (attached), which seems quite straightforward to convert (with a 2s2 2p4 configuration, and no other l in the potential): do you think that with these commands the result should be correct? Even if I do not give the local projector originally used? $ ./cpmd2upf.x Input file > O_MT_GIA_BLYP Oxygen 2s2 2p4 BLYP rc= 1.05 1.05 lmax to use. (max. 1) > 1 l local (max. 1) > 1 Wavefunction # 1: label, occupancy > 2S, 2.0 Wavefunction # 2: label, occupancy > 2P, 4.0 Pseudopotential successfully converted Output PP file in UPF format : O_MT_GIA_BLYP.UPF Thanks in advance, Merlin M?heut On 25/11/2011 17:24, Axel Kohlmeyer wrote: > On Fri, Nov 25, 2011 at 11:02 AM, Merlin Meheut > <merlin.meheut at get.obs-mip.fr> wrote: >> Hi Axel, >> >> Thanks for your help, >> >> To have some understanding on the problem, I compared the original and >> converted pseudopotential files: if they are not exactly the same, >> the spatial grid (<PP_R> in the UPF file, first column of all fields for >> CPMD format), the wavefunction values (for 2S and 2P:<PP_PSWFC> >> in the UPF file,&WAVEFUNCTION in CPMD) , and the NLCC fields >> (<PP_NLCC> in the UPF file,&NLCC in CPMD) are exactly the same in both >> files. I was not too much worried about the nlcc correction, for this >> reason... >> >> However, for the rest of the file, the CPMD file has only a&POTENTIAL >> field wit 2S and 2P potentials, whereas the UPF file have<PP_RAB> , >> <PP_LOCAL>, and<PP_NONLOCAL> fields, and I do not see any agreement >> between the two. What should be the connection? > with CPMD potentials you have to indicate the local potential > in the CPMD input file and then the kleinman-bylander procedure > is done internally in CPMD, whereas in UPF this is already > encoded in the pseudopotential. CPMD also offers to use > gauss-hermite integration instead of kleinman-bylander > (more expensive, but may be needed to avoid ghost > states, e.g. for transition metals). > >> The cpmd file seems quite simple, with two wavefunctions, two potentials >> and one nlcc field. Where is the difficulty of the conversion? >> How are the two formats differing for the potentials? Since I have the >> same values for the wavefunctions, spatial grid and nlcc, >> shouldn't I have the same also for potentials? Maybe this is related to >> a wrong choice for the local part? > the problems are related to having to anticipate correctly > the transformations, regridding, and re-normalizations that > CPMD is doing. add to that that the occasional factor 2 > since CPMD uses hartree atomic units while Q-E uses > rydberg atomic units. > >> By the way, I began by the most difficult case: the O, H and Si >> pseudopotentials I have do not contain nlcc corrections: >> do you think that I can trust the conversion, even if I do not give the >> correct local l? > it is always better to start with the easiest case and > make sure that it works. i am not saying that it is > impossible what you want to do, but one has to make > fairly detailed tests and know how the potentials were > created to fill in the blanks. for exactly that reason, > i found it simpler to start from a consistent atomic > code that can produce both, CPMD format and UPF > output, and then feed those potentials to both codes > to see, if they can work well. > >> My problem for re-generating a pseudo is that I am not quite confident >> in which recipe to use... Especially for Li.... > Li is a quite difficult case. i think the NLCC version > only works well for metallic Li and you may be better > off to do a "semi-core" style potential for ionic Li. > >> Since you say cpmd comments can't be trusted, do you think rc are all >> bogus? > cannot trusted means, that you don't know. some are correct, > some are bogus. it all depends on who created the potential > and what this person assumed about how and by whom the > potential will be used. most are more-or-less accurate. > often you can tell bogus entries if the energy eigenvalue is > identical to the previous state. but i also have seen potentials, > where the comment section was that of a completely different potential... > > that is what i mean by unreliable... you can't really know from the file. > > axel. > >> Best regards, >> >> Merlin M?heut >> >> >> >> On 25/11/2011 16:03, Axel Kohlmeyer wrote: >>> On Fri, Nov 25, 2011 at 9:27 AM, Merlin Meheut >>> <merlin.meheut at get.obs-mip.fr> wrote: >>>> Dear pwscf users, >>>> >>>> I am trying to obtain consistent pseudopotentials to use in both CPMD and >>>> pwscf, precisely for O,H, Si and Li atoms. >>>> I therefore took pseudopotentials from CPMD and tried the cpmd2upf.x >>>> converter. >>>> >>>> I am however not sure of what I should do. In particular, I am not sure of >>>> the local reference state used in these pseudos. >>>> Does this have an influence on the conversion, or is that just an >>>> information written somewhere in comment in the UPF pseudopotential? >>>> More generally, I am not sure of the recipes used to generate these >>>> pseudos, and in which >>>> extent they should be considered in the conversion. THe only information I >>>> have is inside the preamble of the pseudopotential files >>>> (Pseudopotential report), which is reproduced below: >>>> >>>> For example, for the Li atom, I attached the cpmd pseudopotential and here >>>> are the instructions I gave for conversion: >>>> >>>> $ ./cpmd2upf.x >>>> Input file> Li_MT_BLYP_NLCC.psp >>> i don't think that anybody every got the NLCC conversion >>> from CPMD to UPF working correctly. i remember i tried >>> several iterations back and forth with paolo many years >>> ago and then finally went the other route and regenerated >>> pseudopotentials with from the same settings with paulo's >>> atomic code and then converted the output to cpmd format >>> and UPF alike. >>> >>> >>>> amesh set to: 1.002086 >>>> ============================================================ >>>> | Pseudopotential Report Thu Aug 22 12:57:11 1996 | >>>> ------------------------------------------------------------ >>>> | s channel: | >>>> | Atomic Symbol : LI | >>>> | Atomic Number : 3 | >>>> | Number of core states : 1 | >>>> | Number of valence states : 1 | >>>> | Exchange-Correlation Functional : | >>>> | Slater exchange : .6667 | >>>> | LDA correlation : Lee-Yang-Parr | >>>> | Exchange GC : Becke (1988) | >>>> | Correlation GC : Lee-Yang-Parr | >>>> | Electron Configuration : N L Occupation | >>>> | 1 S 2.0000 | >>>> | 2 S 1.0000 | >>>> | Full Potential Total Energy -7.571372 | >>>> | Trouiller-Martins normconserving PP | >>>> | n l rc energy | >>>> | 2 S 2.2000 -.11501 | >>>> | 2 P 2.2000 -.11501 | >>>> | Nonlinear core correction | >>>> | Core charge cutoff radius : 1.80000 | >>>> | Number of Mesh Points : 575 | >>>> | Pseudoatom Total Energy -.205704 | >>>> ============================================================ >>>> | P-channel taken from: | >>>> | 2 S 2.2000 -.21051 | >>>> | 2 P 2.2000 -.13639 | >>>> | 3 D 1.7031 -.13639 | >>>> | Nonlinear core correction | >>>> | Core charge cutoff radius : 1.80000 | >>>> | Number of Mesh Points : 575 | >>>> | Pseudoatom Total Energy -.106791 | >>>> ============================================================ >>>> lmax to use. (max. 1)> 1 >>>> l local (max. 1)> 0 >>>> Wavefunction # 1: label, occupancy> 2S, 1.0 >>>> Wavefunction # 2: label, occupancy> 2P, 0.0 >>>> Pseudopotential successfully converted >>>> Output PP file in UPF format : Li_MT_BLYP_NLCC.psp.UPF >>>> *** PLEASE TEST BEFORE USING!!! *** >>>> review the content of the PP_INFO fields >>>> >>>> >>>> As you can see in the comment of the cpmd potential, the pseudopotential >>>> contains potentials (and wavefunctions) for 2S and 2P, >>>> with the energy of 2P fixed at the same value that 2S. >>> never trust those comments in CPMD pseudopotentials. >>> the atomic code creates bogus entries in there (and >>> nobody seemed to care to fix that issue) and some >>> people "fix" them afterwards, others don't and some >>> actually "fix" those tables incorrectly. several potentials >>> also mix results from different calculations and then >>> the comments can be completely bogus. >>> >>>> I am not sure of what recipe it corresponds to: is that some sort of >>>> Hamann's approach? >>> the atomic code shipped with CPMD is based on >>> hamann's code, but heavily hacked. >>> >>>> Of course, I could test these converted pseudopotentials, but I would like >>>> to be aware of potential problems before. >>> i would be very, *very* careful. particularly >>> on pseudopotentials with NLCC. i suspect, >>> but never found proof, that there are some >>> cases where a bug in the atomic code related >>> to NLCC is compensated by a corresponding >>> bug in the CPMD code. >>> >>> axel. >>> >>>> I would be very thankfull for any help, >>>> >>>> Best regards, >>>> >>>> Merlin M?heut >>>> >>>> -- >>>> Merlin M?heut >>>> adresse labo: >>>> G?osciences Environnement Toulouse >>>> OMP - Universit? Paul Sabatier >>>> 14 avenue Edouard Belin >>>> 31400 Toulouse >>>> FRANCE >>>> tel: (+33) 5 61 33 26 21 >>>> adresse personelle: >>>> 3 rue du Puits Vert >>>> 31000 Toulouse >>>> port: (+33) 6 34 67 57 02 >>>> pseudo skype: quantification >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum at pwscf.org >>>> http://www.democritos.it/mailman/listinfo/pw_forum >>>> >>>> >>> >> >> -- >> Merlin M?heut >> adresse labo: >> G?osciences Environnement Toulouse >> OMP - Universit? Paul Sabatier >> 14 avenue Edouard Belin >> 31400 Toulouse >> FRANCE >> tel: (+33) 5 61 33 26 21 >> adresse personelle: >> 3 rue du Puits Vert >> 31000 Toulouse >> port: (+33) 6 34 67 57 02 >> pseudo skype: quantification >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > > -- Merlin M?heut adresse labo: G?osciences Environnement Toulouse OMP - Universit? Paul Sabatier 14 avenue Edouard Belin 31400 Toulouse FRANCE tel: (+33) 5 61 33 26 21 adresse personelle: 3 rue du Puits Vert 31000 Toulouse port: (+33) 6 34 67 57 02 pseudo skype: quantification -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: O_MT_GIA_BLYP Url: http://www.democritos.it/pipermail/pw_forum/attachments/20111125/553d7641/attachment.txt
