In the QE-6.0 version of EPW, dipole velocity was defined as

Code: Select all

`vkk(:,ibnd) = 2.0 * REAL (dmef (:, ibndmin-1+ibnd,ibndmin-1+ibnd, ikk))`

Thank you,

Vahid

Vahid Askarpour

Dalhousie University

Halifax, Canada

**Moderator:** hlee

Dear EPW Community,

In the QE-6.0 version of EPW, dipole velocity was defined as

In the latest version, the factor 2 is missing. Are both correct?

Thank you,

Vahid

Vahid Askarpour

Dalhousie University

Halifax, Canada

In the QE-6.0 version of EPW, dipole velocity was defined as

Code: Select all

`vkk(:,ibnd) = 2.0 * REAL (dmef (:, ibndmin-1+ibnd,ibndmin-1+ibnd, ikk))`

Thank you,

Vahid

Vahid Askarpour

Dalhousie University

Halifax, Canada

Since there has been no response, is it safe to assume that one of those versions is incorrect?

Thanks,

Vahid

Thanks,

Vahid

Dear Vahid Askarpour:

Please use the recent versions of EPW.

Since EPW v5.4, the expression of dme has changed to make it include the non-local part of pseudopotential and along with this change, the factor of 2 have been removed.

PS) At this point, I don't remember whether the factor of two should be removed in the expression of dme in the previous versions.

Sincerely,

H. Lee

Please use the recent versions of EPW.

Since EPW v5.4, the expression of dme has changed to make it include the non-local part of pseudopotential and along with this change, the factor of 2 have been removed.

PS) At this point, I don't remember whether the factor of two should be removed in the expression of dme in the previous versions.

Sincerely,

H. Lee

Dear H. Lee,

Thank you for your response. Upto qe-6.7MAX, the factor 2 is included in the velocity expression. Only 6.8 and 7.0 have removed the 2.

Thanks,

Vahid

Thank you for your response. Upto qe-6.7MAX, the factor 2 is included in the velocity expression. Only 6.8 and 7.0 have removed the 2.

Thanks,

Vahid