[Wien] Problems with rutile structure with inorb

[Guoping Zhang]

Dear Prof. Blaha and wien users,

I have some questions on the rutile structure in materials such as
TiO2 or RuO2.  Nonmagnetic structures have group symmetry of
136_P42/mnm. For the magnetic ordering, I split the Ru atom into two,
but then sgroup in Wien2k suggests a new space group 65 (C m m
m). According to your prior answer, it seems to me that I do not need
to accept this new structure, even though there is a warning. Then I
can add SOC and U later. It runs without any problem.

However, if I accept the new structure, 65 (C m m m), then when I add
SOC (with spin polarization along [001]), init_so does not lower the
symmetry (it still has eight symmetry operations). When I run with
-orb, it has errors: Error: check case.outputdmup, symmetry might be
wrong.  I have checked those files
..........................................
 SYMMETRY OPERATION:            2
 in global cartesian coordinate system:
   -1.000000    0.000000    0.000000
    0.000000    1.000000    0.000000
    0.000000    0.000000    1.000000

 in spin coordinate system:
    1.000000    0.000000   -0.000000
    0.000000   -0.000000    1.000000
   -0.000000    1.000000    0.000000

 2 Euler angles: a,b,c:    270.0   90.0  270.0
 # of operation, phase, det:
           2  0.000000000000000E+000 -2.220446049250314E-016

 symm. operation            2  so-det= -2.220446049250314E-016
..........................................

I do not understand why the determinant is zero here, but clearly it
is not.

Here are my questions.

(1) Does sym.f in lapwdm have a bug? Or this is due to the failure of
init_so?

(2) What is the general rule to accept or not to accept a new structure?

(3) Why doesn't init_so of Wien2k_24 lower the symmetry ?  Wien2k_13
does lower the symmetry, but there is a different bug in mixer.F
(write(22,*)':WARNING: K-list has changed should be commented out).


I would appreciate any help that you could provide.

Best wishes,

Guoping
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