[Wien] negative grr values in mBJ calculation causing lapw0 to fail

[Neil Johnson]

Hello all,

I am attempting to perform an mBJ calculation using the steps listed in 
sec 4.5.8 of the user's manual. However, lapw0 keeps failing in the 
final scf cycles after switching to IXC=28. We tracked the problem down 
to a negative GRR (∇ρ/ρ = -36.0544), the square root of which is taken 
to calculate "c for IXC=28" in lapw0. Taking the square root of a 
negative number is generally frowned upon, and the program spits out a 
lot of "NaN"s before failing.

Has anyone experienced this problem before, or know what would cause 
lapw0 -grr to produce a negative GRR value?

I've posted the output0 and output0_grr files to 
http://homepage.usask.ca/~nwj781/lapw0/ 
<http://homepage.usask.ca/%7Enwj781/lapw0/> for reference. Thanks!

Cheers,

Neil Johnson
University of Saskatchewan
Saskatoon, Canada