[Wien] Structure relaxation for WO3 with atomic insertion

[Gavin Abo]

In addition to the comments by the others, you might also check for the 
monoclinic if using beta as not equal 90 (where you have beta=90.881 
below) for optimization is okay or not by referring the following link:


https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg12124.html


On 6/14/2020 1:26 PM, Israel Omar Perez Lopez wrote:
>
> Dear Wien2k experts
>
> I am trying to do structure relaxation for WO3 with Li+ insertion for 
> three different phases: cubic [SG Pm-3m (221)], hexagonal [SG P6/mmm 
> (191)] and monoclinic [SG=P2_1 /n (14)] (no supercell in all cases).
>
> For monoclinic I am working with
>
> a=13.8066, b=14.2485 and c=14.5357, alpha=90, beta=90.881, gamma=90; 
> with O1 x=0.284, y=0.2605, z=0.2848; O2 x=0.2827, y=0.0383, z=0.0046; 
> O3 x=0.0025, y=0.035, z=0.2106; O4 x=0.2099, y=0.2568, z=0.7318; W1 
> x=0.2538, y=0.0353, z=0.7807; W2 x=0.2465, y=0.0269, z=0.2859; O5 
> x=0.2856, y=0.4840, z=0.9944; O6 x=0.9974, y=0.4636, z=0.2161; Li
>
> x=y=z=0.5. With RMT for O=1.50, W=1.70 and Li=1.35.
>
>
> For the initialization I used default parameters except RKmax=6 and a 
> k-mesh of 4X4X4 (all atoms were set to nonmagnetic).
>
>
> To do relaxation I ran optimize with option 7 .This asks for the 
> number of structures which I set to 15 and 3% of difference for each 
> structure. Then I set the otimize.job script to
>
>
> min -I -j "run_lapw -I -ec 0.001 -cc 0.001 -fc 5.0 -i 40 -p"
>
>
> as suggested by L. D. Marks in the optimization notes. The program 
> stopped due to an error related to sphere overlapping between O and W. 
> I guess this problem is related to a big percentage (3%) so I started 
> over, also set 15 structures but 1% of difference with
>
> min -I -j "run_lapw -I -ec 0.001 -cc 0.001 -fc 2.0 -i 40 -p"
>
> This time the following errors showed up after a day of doing 
> calculations:
>
>
> Cholesky INFO = 4263
>
> 'SECLR4' - POTRF (Scalapack/LAPACK) failed.
>
>
> And an error in mini.error
>
> STOP in MINI, FORCES small
>
>
> I don't know if the first error caused the second one or viceversa. 
> What I am doing wrong?
>
>
> For the hexagonal case I am using this:
>
> a=b=13.7912 Bohr, c=7.3680 Bohr, alpha=beta=90, gamma=120, and 
> positions W, x=0.5, y=z=0, O1 x=z=0.5 y=0 and O2 x=0.212, y=0.424 and 
> z=0 with RMT values of W=1.7, O=1.5 and Li=1.35. Default initial 
> parameters with a k-mesh 4X4X8.
>
>
> To do relaxation I ran optimize with option 2 (for C/A ratio) and set 
> the percentages to (15,7,0,-7,-15)% (before I also tried 12, 6, 0, -6, 
> -12 no minimium either, linear distribution), then I set the script 
> optimize.job to
>
> min -I -j "run_lapw -I -ec 0.001 -cc 0.001 -fc 5.0 -i 40 -p"
>
> The forces converged but no minimum point was observed in energy vs 
> volume, the point distribution was not parabolic although the fitting 
> was a parabola. Am I doing something wrong?
>
>
> For the cubic case I am using a=7.056237 Bohr, W  x=x=z=0 and O x=0.5, 
> 0, 0. RMT for W=1.83 and O=1.57. Li is inserted at Li 
> x=y=z=0.5withRMTLi=1.5. Initialization is with default parameters 
> except a k-mesh 4X4X8. Then I run anscfcycle with fc=1.0 but the 
> program immediately stops showing up an error reading this:
>
>
>  LAPW0 END
>
> Force-convergence not possible. Forces not present.
> grep: lapw2*.error: No such file or directory
>
> The same happens if I try to run minimization with either mode.
>
>
> Could you please advice what is the right way to proceed for structure 
> relaxation in these three cases? I would appreciate it.
>
>
>
> Best regards
>
>
> Israel
>

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