Parameters for calculating modulus

Parameters here are for calculating elastic modulus. The elastic modulus is defined as the square matrix of second-order partial derivatives of the total energy per volume with respect to the strain tensor.


possible values: a double number

default value: 0.02

description: A small displacement of strain used to calculate the modulus numerically by the differences of stress.

an example: = 0.01


keyword: calculation.modulus.order

possible values: 2, 3, or 5

default value: 3

description: The number of points used to calculate the derivative of force numerically.

an example:

calculation.modulus.order = 2


keyword: calculation.modulus.vdwInteractionQ

possible values: true or false

default value: false

description: If true, van der Waals interaction will be included.

an example:

calculation.modulus.vdwInteractionQ = true


keyword: calculation.modulus.vdwInteractionParameter.method

possible values: ‘Grimme’

default value: ‘Grimme’

description: The parameter vdwInteractionParameter is a structure with many fields. Here the field method gives the method for the van der Waals interaction calculation. For how to set other fields of the structure, please refer to the description of the parameter calculation.vdwForce.

an example:

calculation.modulus.vdwInteractionParameter = []