Calculate the 2nd and 3rd elastic constant.
Online Help (Under writing)
The perl version for CASTEP in Materials Studio were shown in https://github.com/hitliaomq/MaterialPOST/tree/master/ScriptsForCASTEP/Elastic
Mingqing Liao. (2018, December 24). hitliaomq/ELASTIC3rd: ELASTIC3rd. Zenodo. http://doi.org/10.5281/zenodo.2525580
or
Mingqing Liao, Yong Liu, Puchang Cui e.t. al. Elastic3rd: A tool for calculating third-order elastic constants from first principles submitted to computer physics communication (2019)