Monoclinic structure symmetry

[zaz]

Hi every one!
I'm studying a monoclinic structure: with those parameters:
a= 51.9206 0.0000 0.00000
b= 4.40250 0.0000 0.000000000000000000
c= -2.8882 0.0000 14.221509774949224250
alph=102

But when I run my calculation vasp give me a different symmetry and different parameters. Can some body explaim what is going on?
this is the result in OUTCAR
Analysis of symmetry for initial positions (statically):
=====================================================================
Subroutine PRICEL returns following result:

LATTYP: Found a base centered monoclinic cell.
ALAT = 51.9205800000
B/A-ratio = 0.0847929665
C/A-ratio = 0.9832928752
COS(beta) = -0.9569838650

Lattice vectors:

A1 = ( 25.9602900000, 2.2012500000, 0.0000000000)
A2 = ( 25.9602900000, -2.2012500000, 0.0000000000)
A3 = ( -49.0323504956, 0.0000000000, -14.2215097749)

2 primitive cells build up your supercell.


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


Subroutine GETGRP returns: Found 4 space group operations
(whereof 4 operations were pure point group operations)
out of a pool of 4 trial point group operations.


The static configuration has the point symmetry C_2h.


Analysis of symmetry for dynamics (positions and initial velocities):
=====================================================================
Subroutine PRICEL returns following result:

LATTYP: Found a base centered monoclinic cell.
ALAT = 51.9205800000
B/A-ratio = 0.0847929665
C/A-ratio = 0.9832928752
COS(beta) = -0.9569838650

Lattice vectors:

A1 = ( 25.9602900000, 2.2012500000, 0.0000000000)
A2 = ( 25.9602900000, -2.2012500000, 0.0000000000)
A3 = ( -49.0323504956, 0.0000000000, -14.2215097749)

2 primitive cells build up your supercell.


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


Subroutine GETGRP returns: Found 4 space group operations
(whereof 4 operations were pure point group operations)
out of a pool of 4 trial point group operations.


The dynamic configuration has the point symmetry C_2h.

Thanks a lot for your help!
zaz

[support_vasp]

Hi,

We're sorry that we didn’t answer your question. This does not live up to the quality of support that we aim to provide. The team has since expanded. If we can still help with your problem, please ask again in a new post, linking to this one, and we will answer as quickly as possible.

Best wishes,

VASP