Re: [QE-users] Finite electric field polarisation

2021-01-26 Thread Terry Frankcombe
From: users on behalf of Mostafa Youssef via users Sent: Tuesday, 19 January 2021 7:44 PM To: users@lists.quantum-espresso.org Subject: Re: [QE-users] Finite electric field polarisation Dear Terry, The dipole results need post-processing. One needs to subtract n x

Re: [QE-users] Finite electric field polarisation

2021-01-19 Thread Mostafa Youssef via users
Dear Terry, The dipole results need post-processing. One needs to subtract n x polarization quantum to obtain a meaningful polarization. n is an integer. Consider a simple dielectric like MgO at zero field. pw.x may give you different dipoles in all directions, although physically in all

[QE-users] Finite electric field polarisation

2021-01-18 Thread Terry Frankcombe
Hi folks I am trying to perform some finite field calculations on a moderate-sized cell (~1000 Ang^3), using PW example 10 as a guide. When doing a zero field calculation (all efield_cart zero) the total energy converges happily to whatever level I want (e.g. conv_thr=1.d-9). However, the