ABINIT Discussion Forums

Hello

I try to compute elastic constant for orthorombic structure of LiFePO4 using finite difference because I use PAW

Consider C66

from literature distortion matrix below:

b=0.0001
u = 1/(1-b^2)^(1/2) = 1.000000005

D = (u, b*u, 0)
(b*u, u, 0)
(0, 0, 0)

so:
rprim1 1.000000005 0.0001000000005 0
0.0001000000005 1.000000005 0
0 0 1.000000005

See attached finite difference scheme file

But during calculation(abinit 7.8.1) I see next problem:

--- !BUG
message: |
The Bravais lattice determined only from the primitive
vectors (rprim or angdeg), bravais(1)= 2, is not compatible
with the real one, iholohedry= 3, obtained by taking into
account the symmetry operations. This might be due to an insufficient
number of digits in the specification of rprim (at least 10),
or to an erroneous rprim or angdeg. If this is not the case, then ...
src_file: symbrav.F90
src_line: 182

Am I missed some simple ideas or need to write additional code?

GS calculation if interesting "http://forum.abinit.org/viewtopic.php?f=9&t=2753"

Sincerely yours, Evgenii