Hello all, I am an Abinit beginner. I use Abinit for calculating nonlinear optic response. As I understand first I need to relax structure, for that I need to make primitive cell from conventional and launch Abinit, but I am obtaining error:
--- !ERROR
src_file: m_geometry.F90
src_line: 1242
mpi_rank: 0
message: |
Current rprimd gives negative (R1 x R2) . R3 .
Rprimd = -2.618686E+01 -0.000000E+00 -0.000000E+00
-0.000000E+00 -2.618686E+01 -0.000000E+00
1.309343E+01 1.309343E+01 -1.994089E+01
Action: if the cell size and shape are fixed (optcell==0),
exchange two of the input rprim vectors;
if you are optimizing the cell size and shape (optcell/=0),
maybe the move was too large, and you might try to decrease strprecon.
As I understand, this error statment indicate that I made a mistake in the input.abi file.
Can anybody help me to indicate such error? I will be extremely grateful.
To make primitive unit cell I used Avogadro software. Also, can you, please, tell me what is the regular steps in structure optimization? First I need to find optimal ecut, when k-point greed and it is all?
Here is my input file:
# BPO4 Space group 82 I-4 : computation of the total energy
#
#Definition of the unit cell
acell 1 1 1 Angstroms #
rprim 4.3736800000E+00 0.0000000000E+00 0.00000000000E+00
0.0000000000E+00 4.3736800000E+00 0.00000000000E+00
-2.186840000E+00 -2.186840000E+00 3.3304900000E+00
iatcon 1 #to see atom positions' number in calculation or not if 0 is set
optcell 1
ionmov 2 # 1 - molecular dynamic(not working), 2 should be less than 10 degrees of freedom to optimise, optcell 0 not avaliable
dilatmx 1.05
strprecon 1
tolsym 1e-04
#spgroup 82
# atomic positions in units of cell vectors
xred
0.00000 0.50000 0.50000 # B
0.00000 0.00000 0.00000 # P
0.14006 0.74006 0.25383 # O
0.24086 0.36086 0.74617 # O
0.86006 0.26006 0.25383 # O
0.75914 0.63914 0.74617 # O
#Definition of the atom types and pseudopotentials
ntypat 3 # three types of atoms
znucl 5 15 8 # the atom types are Boron, Phosphorus and Oxygen
# the following norm-conserving pseudopotentials are stored in the abinit distribution, but are freely
# available through www.pseudo-dojo.org
# this set uses the Perdew-Wang parameterization of LDA for the xc model
pp_dirpath "../../"
pseudos "B.psp8, P.psp8, O.psp8"
#Definition of the atoms
natom 6 # six atoms in the cell
typat 1 2 3 3 3 3 # type 1 is Boron,type 2 is Phosphorous, type 3 is Oxygen (order defined by znucl above and pseudos list)
#Definition of the planewave basis set
ecut 10.0 # Maximal kinetic energy cut-off, in Hartree
ecutsm 0.005
#Definition of the k-point grid
kptopt 1 # Option for the automatic generation of k points, taking
# into account the symmetry
ngkpt 6 6 6 # This is a 6x6x6 grid based on the primitive vectors
nshiftk 1 # of the reciprocal space (that form a BCC lattice !),
# repeated four times, with different shifts :
tolmxf 1.0e-6
#Definition of the SCF procedure
nstep 100 # Maximal number of SCF cycles
toldfe 1.0d-6 # Will stop when, twice in a row, the difference
# between two consecutive evaluations of total energy
# differ by less than toldfe (in Hartree)
# This value is way too large for most realistic studies of materials
diemac 5.0 # Although this is not mandatory, it is worth to
# precondition the SCF cycle. The model dielectric
# function used as the standard preconditioner
# is described in the "dielng" input variable section.
# Here, we follow the prescription for bulk silicon.