Hi Gemma, I am not sure that I have the whole answer for you. I too have had trouble at times getting feff8 to run with hydrogen atoms in the cluster. I am CCing my response to the mailing lists for Feff and Ifeffit in hopes that someone else might have some more wisdom for you. The feff.inp file you sent me is appended to the end of this email, in case any of the brains on the mailing lists need to see it. On Tuesday 27 February 2007 11:27, Gemma GUILERA wrote:

I am currently running FEFF8.2 for one of my systems which include some H atoms (as hydrides). These are actually very important in the structure and I want to consider them in the run. For this I used the FOLP function in POT with an overlapping value of 0.8 for H as suggested in the manual. Also, since I think that the AFOLP card gets deactivated, I also added these cards for the rest of the potentials keeping them at 1.15. I obviously do something completely wrong because the program stops and appears an error message of the type:

FOLP for POTENTIAL type 0 is too big. Reduce overlap using FOLP and rerun.

I do not understand what I need to do, because the potential 0 is not the one I am modifying with respect to the default values. I would really appreciate if you could have a look at the feff.inp file and tell me what did I do wrongly...and sorry for wasting your time.

Well, my understanding is that Feff's various overlapping methods do have effects that are not restricted to the ipots that you are explicitly modifying. That is, if you restrain the size of one muffin tin, other muffin tins can get a bit bigger or smaller to compensate. It depends on the geometry and how the atom you are modifying is represented in the cluster. My first thought is that you need to play around with the FOLP value for the absorber. Try smaller values to see if you can get Feff to run to completion. My second thought is to abandon the FOLP keywords and try using AFOLP. Another thought is that you may need to use a larger cluster. Some atom types -- B for example -- have few representatives in your cluster and so their muffin tin radii might be improperly constrained. Does anyone else have any good suggestions for Gemma? B TITLE FeBH6Fe complex EDGE K S02 1.0 * pot xsph fms paths genfmt ff2chi CONTROL 1 1 1 1 1 1 PRINT 1 0 0 0 0 3 * r_scf [ l_scf n_scf ca ] SCF 2.90160 0 15 0.1 * ixc [ Vr Vi ] EXCHANGE 0 0 0 FOLP 0 1.15 FOLP 1 0.8 !Use 0.8 muffin-tin radii overlapping factor for H FOLP 2 1.15 FOLP 3 1.15 FOLP 4 1.15 FOLP 5 1.15 EXAFS RPATH 6 * kmax [ delta_k delta_e ] *XANES 4.0 0.07 0.5 * r_fms [ l_fms ] *FMS 2.90160 0 * *RPATH 0.10000 * emin emax resolution *LDOS -20 20 0.1 POTENTIALS * ipot z [ label l_scmt l_fms stoichiometry ] 0 26 Fe -1 -1 0 1 1 H -1 -1 6 2 5 B -1 -1 1 3 15 P -1 -1 6 4 6 C -1 -1 46 5 26 Fe -1 -1 2 ATOMS 0.00000 0.00000 0.00000 0 Fe1 0.00000 -0.71680 -1.08741 -0.20797 1 H42 1.31891 -1.33000 0.40717 0.04190 1 H41 1.39156 -0.20933 -0.03121 -1.56977 1 H40 1.58398 -1.50973 -0.47766 -1.07196 2 B1 1.91221 0.07929 -0.26849 2.16349 3 P3 2.18152 0.78129 2.03650 0.10939 3 P2 2.18397 2.03623 -0.76920 -0.20440 3 P1 2.18625 -2.30265 0.13209 -1.93594 1 H42 3.01123 -2.81012 -0.92412 -0.57414 1 H40 3.01338 -1.68946 -1.36249 -2.18581 1 H41 3.08033 3.15055 -0.21476 1.16774 4 C22 3.36686 0.19242 -2.02477 2.69082 4 C25 3.37301 2.87884 -0.31857 -1.75462 4 C13 3.38643 1.52559 0.58481 2.96848 4 C24 3.38840 2.32803 2.20201 1.14003 4 C49 3.40121 -0.35734 3.30346 0.81773 4 C37 3.42188 1.28771 2.89227 -1.43362 4 C43 3.47544 2.68114 0.97735 2.02827 4 C23 3.50109 -1.29194 0.30124 3.24246 4 C31 3.50334 2.42741 -2.57443 -0.17395 4 C1 3.54263 1.08472 2.33572 -2.68697 4 C48 3.72183 -2.31005 1.13130 2.75352 4 C36 3.76803 -3.01946 -0.95533 -2.14391 5 Fe1 3.82441 -0.91239 -2.83347 2.42108 4 C26 3.83701 1.44841 -3.56032 -0.07829 4 C3 3.84446 2.35340 -0.84952 -2.93358 4 C15 3.85565 -1.36594 3.79736 -0.00896 4 C38 4.03557 -0.32880 3.71800 2.14367 4 C42 4.30429 1.32048 -2.62656 3.24943 4 C30 4.38193 3.96885 0.55229 -1.84177 4 C21 4.41009 1.89033 4.15594 -1.34798 4 C44 4.76049 -1.27608 0.01031 4.60350 4 C32 4.77710 3.77855 -2.96794 -0.18652 4 C11 4.80842 3.85573 1.40280 2.91662 4 C50 5.03400 -4.10418 -3.29104 0.54306 4 C48 5.28868 -3.80075 -2.99182 -2.25330 3 P2 5.33611 -3.09875 -0.68684 -4.30740 3 P3 5.35048 -2.10707 1.87815 -4.56499 4 C26 5.36715 -0.70940 -2.08663 -4.89743 4 C36 5.37049 -5.05569 -0.18613 -1.93951 3 P1 5.41815 -5.37286 -0.10580 0.78966 4 C15 5.43161 -1.65351 -4.75268 -2.13495 4 C38 5.46627 -4.46787 2.60499 -2.06562 4 C3 5.56908 -1.72752 -1.25656 -5.38637 4 C31 5.79450 -4.30717 -3.84760 -0.71029 4 C43 5.81895 -2.66211 -4.25879 -2.96164 4 C37 5.83056 -3.21187 1.06944 -4.83473 4 C25 5.90207 -5.89830 -0.63676 -0.38929 4 C13 5.94533 END -- Bruce Ravel ---------------------------------------------- bravel@anl.gov Molecular Environmental Science Group, Building 203, Room E-165 MRCAT, Sector 10, Advanced Photon Source, Building 433, Room B007 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793 My homepage: http://cars9.uchicago.edu/~ravel EXAFS software: http://cars9.uchicago.edu/~ravel/software/