[Ifeffit] Strange problem with FEFF 6L.02

[John McLeod]

I realize this problem might be a bit out of scope for this mailing
list, but I was wondering if anyone in the community has any insight
into the matter.

I was playing around with random clusters of atoms and I noticed that
FEFF6 spits out the following error:
   At line 90 of file istprm.f
   Fortran runtime error: End of file
For a few specific geometries. For most of the structures I have tried
FEFF runs fine. I have also tested this on 2 other computers with the
same results (all computers are linux machines though, and all with the
same FEFF 6L.02 distribution from Artemis 0.8.011).

At the end of this email is a sample feff.inp file that produces this
error. The second atom, `Se_2' at position (-3.70, -2.63, -3.38) causes
the problem. If we move `Se_2' to a new position of (-3.71, -2.63,
-3.38) then FEFF runs fine. `Se_2' is over 2.2 angstroms from all other
atoms in the cluster.

If anyone out there is willing to help me out:
1. Has anyone run into this sort of thing before?
2. Does anyone know why it happens?
3. Do you get the same results as I do with the attached feff.inp?
4. Do the later versions of FEFF have the same problem, or is it native
to FEFF6?
5. Is the problem related to my probably outdated version of Artemis?

Thanks in advance,

John McLeod
Department of Physics and Engineering Physics
University of Saskatchewan

-----------------------------------------------
 TITLE Selenium Cluster

 HOLE 1   1.0   

 *         mphase,mpath,mfeff,mchi
 CONTROL   1      1     1     1
 PRINT     1      0     0     3

 RMAX        6.0
 NLEG         4

 POTENTIALS
 *    ipot   Z  element
        0   34   Se        
        1   34   Se        

 ATOMS                          
 *   x          y          z      ipot  tag              distance
 0.0	 0.0	 0.0	0	Se_1	0.0
 -3.70	 -2.63	 -3.38	1	Se_2	  5.66        * this atom causes problems
* -3.71   -2.63   -3.38  1       Se_2      5.66       * this one does
not
 -2.86	 -0.69	 -2.42	1	Se_3	  3.81
 -3.75	  0.32	  3.27	1	Se_4	  4.99
 -3.49	 -2.06	  0.33	1	Se_5	  4.07
 -1.57	 -1.57	  4.15	1	Se_6	  4.71
  0.44	 -4.00	 -2.28	1	Se_7	  4.62
 -1.06	  0.84	  4.08	1	Se_8	  4.29
 -2.92	  1.59	 -3.13	1	Se_9	  4.56
 -3.46	  3.66	 -1.11	1	Se_10	  5.16
 -4.87	  2.90	  1.37	1	Se_11	  5.83
 -2.64	 -3.53	 -1.52	1	Se_12	  4.66
  1.34	 -4.46	  1.72	1	Se_13	  4.97
 -0.26	 -0.45	 -4.18	1	Se_14	  4.21
 -1.52	 -3.36	 -3.14	1	Se_15	  4.84
 -4.85	 -0.91	  0.69	1	Se_16	  4.99
 -0.93	 -4.90	  0.37	1	Se_17	  5.00
 -0.41	  1.95	 -3.19	1	Se_18	  3.76
  0.20	 -3.09	  2.43	1	Se_19	  3.94
 -3.19	  1.28	 -1.23	1	Se_20	  3.65
 -1.02	  1.69	 -5.66	1	Se_21	  5.99
  0.07	  3.30	  3.46	1	Se_22	  4.78
 -1.67	  4.62	 -3.18	1	Se_23	  5.85
  2.23	 -3.69	 -3.68	1	Se_24	  5.67
  1.94	 -0.35	 -4.32	1	Se_25	  4.75
  1.23	  3.89	 -3.49	1	Se_26	  5.37
 -2.89	  3.59	  1.53	1	Se_27	  4.86
  3.71	 -1.40	 -2.73	1	Se_28	  4.82
 -1.06	  4.39	 -0.12	1	Se_29	  4.51
  3.77	 -3.51	 -0.02	1	Se_30	  5.15
  2.74	  3.06	  2.59	1	Se_31	  4.86
  2.90	 -1.96	  4.77	1	Se_32	  5.92
  2.44	  1.72	  3.98	1	Se_33	  4.97
  2.61	  4.96	 -0.31	1	Se_34	  5.61
END
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