LCALCEPS: Difference between revisions

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from the [[Berry_phases_and_finite_electric_fields#Self-consistent_response_to_finite_electric_fields|self-consistent response to finite electric fields]] <span style="font-size:16pt">''&epsilon;''</span>.
from the [[Berry_phases_and_finite_electric_fields#Self-consistent_response_to_finite_electric_fields|self-consistent response to a finite electric field]] <span style="font-size:16pt">''&epsilon;''</span>.
In this case, the "response" of the system is the change in the polarization '''P''', the Hellmann-Feynman forces '''F''', and the stress tensor &sigma;.
In this case, the "response" of the system is the change in the polarization '''P''', the Hellmann-Feynman forces '''F''', and the stress tensor &sigma;.



Revision as of 12:59, 19 March 2011

LCALCEPS = .TRUE. | .FALSE.
Default: LCALCEPS = .FALSE. 

Description: for LCALCEPS=.TRUE. the macroscopic ion-clamped static dielectric tensor, Born effective charge tensors, and the ion-clamped piezoelectric tensor of the system are determined from the response to finite electric fields.


For LCALCEPS=.TRUE., VASP calculates the ion-clamped static dielectric tensor

the Born effective charge tensors

and the ion-clamped piezoelectric tensor of the system

from the self-consistent response to a finite electric field ε. In this case, the "response" of the system is the change in the polarization P, the Hellmann-Feynman forces F, and the stress tensor σ.

Related Tags and Sections

LEPSILON, LCALCPOL, EFIELD_PEAD, LPEAD, IPEAD, LBERRY, IGPAR, NPPSTR, DIPOL, Berry phases and finite electric fields


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