Type

Strain

$\Delta E/V_0$

(0)

isotropic

$e_1=\delta$

$e_2=\delta$

$e_3=\delta$

(see bulk modulus)

(1)

monoclinic

$e_1={\delta }^2/\left(1-{\delta }^2\right)$

$e_4=\delta$

$2c_{44}{\delta }^2+O\left({\delta }^4\right)$

(2)

triclinic

$e_3={\delta }^2/\left(1-{\delta }^2\right)$

$e_6=\delta$

$2c_{66}{\delta }^2+O\left({\delta }^4\right)$

(3)

orthorhombic

$e_1=\delta$

$e_2=-\delta$

$e_3={\delta }^2/\left(1-{\delta }^2\right)$

$\left(c_{11}-c_{12}\right){\delta }^2+O\left({\delta }^4\right)$

(4)

orthorhombic

$e_1=\delta$

$e_2={\delta }^2/\left(1-{\delta }^2\right)$

$e_3=-\delta$

$\left(c_{11}-2c_{13}+c_{33}\right){\delta }^2/2+O\left({\delta }^4\right)$

(5)

tetragonal

$e_1=\delta$

$e_2=\delta$

$e_3=-\delta \left(2+\delta \right)/{\left(1+\delta \right)}^2$

$\left(c_{11}+c_{12}+2c_{33}-4c_{13}\right){\delta }^2/2+O\left({\delta }^4\right)$

(6)

tetragonal

$e_3=\delta$

$c_{33}{\delta }^2/2$