[Wien] Mixer probelem

[Igor I Mazin]

I cannot get my test run past MIXAR. I have done thousands of WIEN 
calculations in my life, with all sort of complex structures, and cannot 
get this one simple bcc test case.

here is the head of my struct file:

--------

test

B   LATTICE,NONEQUIV.ATOMS:  1 229 Im-3m
              RELA
   5.635160  5.635160  5.635160 90.000000 90.000000 90.000000
ATOM   1: X=0.00000000 Y=0.00000000 Z=0.00000000
           MULT= 1          ISPLIT= 2
Fe1        NPT=  781  R0=.000050000 RMT= 2.33        Z:  26.
...

-----

note that RMTs are not overlapping.

I do  ' init -s nn -b'
No changes; then just 'run'. Here is the output:
  LAPW0 END
  LAPW1 END
  LAPW2 END
  CORE  END
Mixer - Error, No feasible Pratt step
 >   stop error

If I change mixing to PRATT in case.inm (PRATT   0.0   YES   // 0.20 
//1.00  1.00//9999  8)
and clean_lapw to remove broyden files, I get

  LAPW0 END
  LAPW1 END
  LAPW2 END
  CORE  END
  MIXER END
if: Expression Syntax.

I can ran x mixer manually,  x mixer
  MIXER END
0.022u 0.015s 0:00.03 100.0%    0+0k 0+192io 0pf+0w

but then the charge densities are messed up, because LAPW1 bombs with 
the "SELECT - Error" message.

This behavior persists even if the mixing parameter is reduced to 
essentially zero.

If I replace this bcc lattice with fcc of the same density, there is no 
error. If I run the same bcc lattice in the conventional two-atom cell, 
the error disappears.


This is probably the weirdest behavior I ever saw in WIEN, and I've seen 
a lot...


-- 
Igor Mazin, Prof. of Advanced Studies
Quantum Science and Engineering Center
Department of Physics and Astronomy
George Mason University
phone 1-703-503-8152 (h)
http://mason.gmu.edu/~imazin2