18.1.2 B86MGC: X ${\alpha \beta \gamma }$ with Modified Gradient Correction

A. D. Becke, J. Chem. Phys. 85, 7184 (1986)

B86 with modified gradient correction for large density gradients.

$$K= \sum_s -c\rho_{s}^{4/3}-{\frac {\beta \chi_{s}^ {2}\rho_{s}^{4/3}}{\left (1+\lambda \chi_{s} ^{2}\right )^{4/5}}} ,$$ (10)

where

$$c=\frac{3}{2}\left (\frac{3}{4\pi}\right )^{1/3} ,$$ (11)

$$\beta= 0.00375$$ (12)

and

$$\lambda= 0.007 .$$ (13)