Help with the symmetry and type of cell

[kmkumar]

Dear Friends,
I am new user to VASP and aplogies if the question is naive.

I wish to find out the Total energy of the cell which is bcc and
has pnma (D2h) space group.

I set the poscar (given below) and Isym=2, symprec=1e-5 and the output shows the following.

The symmetry is predicted correctly, but it says that the structure of the cell is orthorombic.

Is this correct, Am i going wrong... Please suggest.

Here is a part of OUTCAR


--------------------------------------------------
LATTYP: Found a simple orthorhombic cell.
ALAT = 6.4590000000
B/A-ratio = 1.7603344171
C/A-ratio = 1.8492026630

Lattice vectors:

A1 = ( 0.0000000000, 0.0000000000, -6.4590000000)
A2 = ( 0.0000000000, -11.3700000000, 0.0000000000)
A3 = ( -11.9440000000, 0.0000000000, 0.0000000000)
Subroutine PRICEL returns:
Original cell was already a primitive cell.


Analysis of symmetry for initial positions (statically):

Routine SETGRP: Setting up the symmetry group for a
simple orthorhombic supercell.


Subroutine GETGRP returns: Found 8 space group operations
(whereof 2 operations were pure point group operations)
out of a pool of 8 trial point group operations.


The static configuration has the point symmetry S_2 .
The point group associated with its full space group is D_2h.

Analysis of symmetry for dynamics (positions and initial velocities):

Subroutine DYNSYM returns: Found 8 space group operations
(whereof 2 operations were pure point group operations)
out of a pool of 8 trial space group operations
(whereof 2 operations were pure point group operations)
and found also 1 'primitive' translations


The dynamic configuration has the point symmetry S_2 .
The point group associated with its full space group is D_2h.

Analysis of constrained symmetry for selective dynamics:

Subroutine DYNSYM returns: Found 8 space group operations
(whereof 2 operations were pure point group operations)
out of a pool of 8 trial space group operations
(whereof 2 operations were pure point group operations)
and found also 1 'primitive' translations


The constrained configuration has the point symmetry S_2 .
The point group associated with its full space group is D_2h.

Analysis of magnetic symmetry:

Subroutine MAGSYM returns: Found 8 space group operations
(whereof 2 operations were pure point group operations)
out of a pool of 8 trial space group operations
(whereof 2 operations were pure point group operations)
and found also 1 'primitive' translations


The magnetic configuration has the point symmetry S_2 .
The point group associated with its full space group is D_2h.
----------------------------------------


POSCAR C O W
1.00000000000000
11.9440000000000008 0.0000000000000000 0.0000000000000000
0.0000000000000000 11.3699999999999992 0.0000000000000000
0.0000000000000000 0.0000000000000000 6.4589999999999996
24 24 4
Selective dynamics
Direct
0.0262599997222424 0.1246499940752983 1.1823999881744385 T T T
0.2263699918985367 0.1232799962162972 0.9377999901771545 T T T
0.4737400002777577 -0.1246499940752983 1.6823999881744385 T T T
0.2736300081014633 -0.1232799962162972 1.4377999901771545 T T T
-0.0262599997222424 0.6246499940752983 -1.1823999881744385 T T T
-0.2263699918985367 0.6232799962162972 -0.9377999901771545 T T T
0.5262599997222424 0.3753500059247017 -0.6823999881744385 T T T
0.7263699918985367 0.3767200037837029 -0.4377999901771545 T T T
-0.0262599997222424 -0.1246499940752983 -1.1823999881744385 T T T
-0.2263699918985367 -0.1232799962162972 -0.9377999901771545 T T T
0.5262599997222424 0.1246499940752983 -0.6823999881744385 T T T
0.7263699918985367 0.1232799962162972 -0.4377999901771545 T T T
0.0262599997222424 0.3753500059247017 1.1823999881744385 T T T
0.2263699918985367 0.3767200037837029 0.9377999901771545 T T T
0.4737400002777577 0.6246499940752983 1.6823999881744385 T T T
0.2736300081014633 0.6232799962162972 1.4377999901771545 T T T
0.0333999991416931 0.2500000000000000 0.8011999726295471 T T T
0.2217999994754791 0.2500000000000000 0.3225999772548676 T T T
0.4666000008583069 -0.2500000000000000 1.3011999726295471 T T T
0.2782000005245209 -0.2500000000000000 0.8225999772548676 T T T
-0.0333999991416931 0.7500000000000000 -0.8011999726295471 T T T
-0.2217999994754791 0.7500000000000000 -0.3225999772548676 T T T
0.5333999991416931 0.2500000000000000 -0.3011999726295471 T T T
0.7217999994754791 0.2500000000000000 0.1774000227451325 T T T
-0.0317000001668930 0.0537599995732307 1.2526999711990356 T T T
0.2816599905490875 0.0511199980974197 0.8709999918937683 T T T
0.5317000001668930 -0.0537599995732307 1.7526999711990356 T T T
0.2183400094509125 -0.0511199980974197 1.3709999918937683 T T T
0.0317000001668930 0.5537599995732307 -1.2526999711990356 T T T
-0.2816599905490875 0.5511199980974197 -0.8709999918937683 T T T
0.4682999998331070 0.4462400004267693 -0.7526999711990356 T T T
0.7816599905490875 0.4488800019025803 -0.3709999918937683 T T T
0.0317000001668930 -0.0537599995732307 -1.2526999711990356 T T T
-0.2816599905490875 -0.0511199980974197 -0.8709999918937683 T T T
0.4682999998331070 0.0537599995732307 -0.7526999711990356 T T T
0.7816599905490875 0.0511199980974197 -0.3709999918937683 T T T
-0.0317000001668930 0.4462400004267693 1.2526999711990356 T T T
0.2816599905490875 0.4488800019025803 0.8709999918937683 T T T
0.5317000001668930 0.5537599995732307 1.7526999711990356 T T T
0.2183400094509125 0.5511199980974197 1.3709999918937683 T T T
-0.0182699989527464 0.2500000000000000 0.6538000106811523 T T T
0.2741799950599670 0.2500000000000000 0.4731999933719635 T T T
0.5182699989527464 -0.2500000000000000 1.1538000106811523 T T T
0.2258200049400330 -0.2500000000000000 0.9731999933719635 T T T
0.0182699989527464 0.7500000000000000 -0.6538000106811523 T T T
-0.2741799950599670 0.7500000000000000 -0.4731999933719635 T T T
0.4817300010472537 0.2500000000000000 -0.1538000106811523 T T T
0.7741799950599670 0.2500000000000000 0.0268000066280365 T T T
0.1272300034761429 0.2500000000000000 0.0630199983716011 T T T
0.3727699965238571 -0.2500000000000000 0.5630199983716010 T T T
-0.1272300034761429 0.7500000000000000 -0.0630199983716011 T T T
0.6272300034761429 0.2500000000000000 0.4369800016283990 T T T

[alex]

Your cell is orthorhombic and far away from cubic ...

11.9440000000000008 0.0000000000000000 0.0000000000000000
0.0000000000000000 11.3699999999999992 0.0000000000000000
0.0000000000000000 0.0000000000000000 6.4589999999999996

Alex