Hi, I am very new to the modern theory of polarization and berry phase. But I want to know if the calculation of spontaneous polarization in siesta follows the modern approach proposed by Dr. Resta et al.
Also, I have calculated the alteration of polarization along "C" for ZnO and I have got the enclosed results. I am not getting close to the results published in papers for piezo coefficient e33 (which equals to sth around 1.19 C/m^2). Seems that the slope is far larger than it should be. Any comments about calculating e33 (C/m^2)? Thanks in advance for your responses. Regards, Pedram Heidari
Strain Polarization (debye) 0.04 330.099002 0.035 328.388191 0.03 326.641522 0.025 324.922515 0.02 323.250741 0.015 321.517311 0.01 319.779862 0.005 317.935534 0 316.141328 -0.005 314.36801 -0.01 312.619537 -0.015 310.857181 -0.02 309.086213 -0.025 307.373585 -0.03 305.568515 -0.035 303.719966 -0.04 301.961325
