Why is VASP changing my lattice vectors and how to avoid it.
Posted: Thu Mar 08, 2012 7:28 pm
Dear all,
I find that when I am trying to do a Berry phase calculation within the HSE06 scheme, VASP changes my lattice vectors. That is, I have a ZB primitive unit cell as input
LATTYP: Found a face centered cubic cell.
ALAT = 4.3637300000
Lattice vectors:
A1 = ( 0.0000000000, 2.1818650000, 2.1818650000)
A2 = ( 2.1818650000, 0.0000000000, 2.1818650000)
A3 = ( 2.1818650000, 2.1818650000, 0.0000000000)
But for the Berry phase HSE06 calculation VASP does the following to my cell
LATTYP: Found a base centered monoclinic cell.
ALAT = 5.3444559376
B/A-ratio = 0.5773502692
C/A-ratio = 0.8164965830
COS(beta) = -0.7070714241
Lattice vectors:
A1 = ( 2.1818650000, 0.0000000000, 2.1818650000)
A2 = ( 2.1818650000, 2.1818650000, 0.0000000000)
A3 = ( -4.3637300000, 0.0002181865, 0.0002181865)
This changes the geometry of the cell and reduces the symmetry! How can I avoid it?
I find that when I am trying to do a Berry phase calculation within the HSE06 scheme, VASP changes my lattice vectors. That is, I have a ZB primitive unit cell as input
LATTYP: Found a face centered cubic cell.
ALAT = 4.3637300000
Lattice vectors:
A1 = ( 0.0000000000, 2.1818650000, 2.1818650000)
A2 = ( 2.1818650000, 0.0000000000, 2.1818650000)
A3 = ( 2.1818650000, 2.1818650000, 0.0000000000)
But for the Berry phase HSE06 calculation VASP does the following to my cell
LATTYP: Found a base centered monoclinic cell.
ALAT = 5.3444559376
B/A-ratio = 0.5773502692
C/A-ratio = 0.8164965830
COS(beta) = -0.7070714241
Lattice vectors:
A1 = ( 2.1818650000, 0.0000000000, 2.1818650000)
A2 = ( 2.1818650000, 2.1818650000, 0.0000000000)
A3 = ( -4.3637300000, 0.0002181865, 0.0002181865)
This changes the geometry of the cell and reduces the symmetry! How can I avoid it?