ABINIT Discussion Forums

Dear all,

I started from a tetragonal bravais lattice
#-----------------------------
acell 10.0826 20.1653 15.3668
angdeg 90 90 90
#-------------------------------
but in the run, abinit tells me
#--------------------------------
symbrav : COMMENT -
The Bravais lattice determined only from the primitive
vectors, bravais(1)= 3, is more symmetric
than the real one, iholohedry= 2, obtained by taking into
account the atomic positions. Start deforming the primitive vector set.

symlatt : the Bravais lattice is mP (primitive monoclinic)
symspgr : the symmetry operation no. 1 is the identity
symplanes : the symmetry operation no. 2 is an a,b, or c plane
symspgr : spgroup= 7 Pc (=Cs^2)
#-------------------------------------

I wonder what happens here. Is abinit trying to find another set of primitive vectors?

Thanks a lot!

Hard to say without seeing your entire input file. Note that your acell choice is orthorhombic, not tetragonal...can you post your input file and/or send it to me?

The warning is quite clear - the lattice is orthorhombic but you have a basis of atoms which breaks all available symmetries. It's not a problem unless you were expecting to preserve some symmetry. The message from abinit is just a comment, no error is present.