[QE-users] change lattice constant for orthorhombic structure

[Davide Ceresoli]

Instead of doing a constant volume relaxation (calculation='relax'),
do a constant pressure relaxation (calculation='vc-relax', press=....).
This way you will obtain E(V) where E=E(P), V=V(P) and the enthalpy
H(P) = E(P) + P*V(P).

HTH.

D.



On 10/27/21 11:05 AM, Pooja Vyas wrote:
> Dear users,
> I have obtained equilibrium parameters for my orthorhombic system which has 
> ibrav=8 and lattice constants A, B and C in Angstroms. Now, I need energy vs. 
> lattice constant curve, for which I require to change the lattice constant. For 
> a cubic system only 'a' is used and hence only 'a' used to change. But can I 
> know what could be the correct way for changing lattice constants for 
> orthorhombic? If I change 'a' in step of 0.05 angstrom, then how should I change 
> B and C?
> 
> Any kind of help is appreciated.