HFALPHA: Difference between revisions
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{{TAG|HFALPHA}} sets the decay constant in the error-function-like charge distribution for the method of Massida, Posternak, and Baldereschi{{cite|massidda:prb:93}}. The error-function-like charge distribution is used to calculate the difference between the isolated probe charge and the periodically repeated probe charge in a homogenous background. The default for {{TAG|HFALPHA}} is 6/sqrt({{TAG|ENMAX}})/(2π) in atomic units. This usually yields robust and accurate results in the range of meV compared to the Ewald summation used for a regular k-mesh. For more details, see {{TAG|HFRCUT}} | {{TAG|HFALPHA}} sets the decay constant in the error-function-like charge distribution for the method of Massida, Posternak, and Baldereschi{{cite|massidda:prb:93}}. The error-function-like charge distribution is used to calculate the difference between the isolated probe charge and the periodically repeated probe charge in a homogenous background. The default for {{TAG|HFALPHA}} is 6/sqrt({{TAG|ENMAX}})/(2π) in atomic units. This usually yields robust and accurate results in the range of meV compared to the Ewald summation used for a regular k-mesh. For more details, see {{TAG|HFRCUT}}. | ||
== Related Tags and Sections == | == Related Tags and Sections == | ||
Revision as of 04:00, 22 July 2021
HFALPHA = [real]
| Default: HFALPHA | = 6/sqrt(ENMAX)/(2π) | if HFRCUT is 0 |
Description: HFALPHA sets the decay constant used in the method of Massida, Posternak, and Baldereschi, which is activated by HFRCUT=0.
HFALPHA sets the decay constant in the error-function-like charge distribution for the method of Massida, Posternak, and Baldereschi[1]. The error-function-like charge distribution is used to calculate the difference between the isolated probe charge and the periodically repeated probe charge in a homogenous background. The default for HFALPHA is 6/sqrt(ENMAX)/(2π) in atomic units. This usually yields robust and accurate results in the range of meV compared to the Ewald summation used for a regular k-mesh. For more details, see HFRCUT.