Dear Alberto,
I have also experienced the same problem with siesta-3.0 version and could
not not find any solution. However, what I have found may relevant and
pertinent to your embarrassment.
I was trying to calculate optical properties of one atomic layer of
graphene (as a test system for siesta 3.0) and I got the same error ('MINVEC:
BASIS VECTORS ARE LINEARLY DEPENDENT').
My lattice vectors were absolutely ok, moreover, this error appears only
when "Optical.calculation .true." , like in your case. Then I looked
throughout siesta archive and found many users experiencing
the same problem. Marcos Verissimo proposed that "by basis vectors siesta
does not mean the lattice vectors, it's related to the basis functions
instead."
As other siesta user suggested, I deceased the size of one of my lattice
vectors in such a way that instead of planar structure I have the bulky
material (graphite, or so). When I did that the error message
no longer appears but SystemLabel.EPSIGM file was not created and
calculations stopped right before the evaluation of dipole moment. This
looks weird.
Then I contacted Dr. Daniel Sanchez and he assumed that "something went
corrupted with this bit of the code during the migration to latest
version". Probably this is a bug. I had to go back to siesta 2.0.
It's even more surprising that you've managed to get your optical
properties with siesta 3.1.
Up to now, that's all I know about this issue.
I would be very obliged if you could send me your .fdf file to check it.
Best regards,
Artem Baskin
Chemistry Department
University of Illinois at Chicago
On Thu, Jan 26, 2012 at 4:10 AM, Alberto <aeljar...@el.ub.es> wrote:
> Dear Siesta Users,
>
> I'm trying to use siesta-ldau to improve an optical calculation of
> Hexagonal GaN. Former calculations in siesta-3.1 with GGAs and LDAs where
> working just nice, but now (using siesta-ldau) i'm getting an error message
> without even changing the calculation: just normal LDA or GGA.
>
> The error message appears only when "Optical.calculation .true." and goes
> like this:
>
> 'MINVEC: BASIS VECTORS ARE LINEARLY DEPENDENT'
>
> Repeated once for each of the processor if running a parallel calculation.
>
> If one searches for the routine minvec.f in the siesta-ldau/Src folder,
> something like this is written in the comments:
>
> C *******************************************************************
> C FINDS THE LATTICE BASIS OF MINIMUM LENGTH, I.E. SUCH TAHT ANY
> C OTHER BASIS (NOT EQUIVALENT BY SYMMETRY) HAS ONE VECTOR LONGER.
> C WRITTEN BY J.MORENO AND J.SOLER. AUGUST 1989 AND OCTOBER 1997.
> C ********* INPUT ***************************************************
> C REAL*8 B0 : Cell vectors B0(xyj,vector)
> C ********* OUTPUT **************************************************
> C REAL*8 BMIN : Minimum cell vectors B0(xyj,vector)
> C *******************************************************************
>
> I guess this error has something to do with the lattice vectors. I run the
> calculation with a fixed lattice like this:
>
> outcell: Cell vector modules (Ang) : 3.208006 3.208006 5.232989
> outcell: Cell angles (23,13,12) (deg): 90.0000 90.0000 120.0000
> outcell: Cell volume (Ang**3) : 46.6392
>
> (I'm pasting the result of "grep outcell output.fdf")
>
> A quick investigation of the mailing-list showed that the misterious force
> behind this error message has not been yet revealed, although some people
> have been complaining about getting the same error message. Everyone of
> them had been trying to execute optical calculations (which I have been
> perfectly able of doing in the my former siesta experiences).
>
> Does anyone have any kind of insight or clue for this problem? If so, help
> would be greatly appreciated.
>
> Thank you in advance,
>
> Alberto Eljarrat Ascunce
> Departamet d'Electrònica,
> Universitat de Barcelona.
>
>
