LTBOUNDLIBXC

TBOUNDLIBXC = .TRUE. | .FALSE.
Default: TBOUNDLIBXC = .FALSE.

Description: TBOUNDLIBXC specifies whether or not the lower bound for the Kohn-Sham kinetic-energy density $\tau_{\sigma}$ ( $\tau_{\sigma}^{\textrm{W}}<\tau_{\sigma}$ ) is enforced before $\tau_{\sigma}$ is used in a meta-GGA functional from Libxc.

The Kohn-Sham kinetic-energy density $\tau_{\sigma}$ should in principle be larger than the von Weizsäcker kinetic-energy density $\tau_{\sigma}^{\textrm{W}}=\left\vert\nabla\rho_{\sigma}\right\vert^{2}/\left(8\rho_{\sigma}\right)$ . However, for numerical reasons this may not always be the case and can potentially lead to problems depending on the meta-GGA. If TBOUNDLIBXC=.TRUE., then $\tau_{\sigma}=\max(\tau_{\sigma},\tau_{\sigma}^{\mathrm{W}})$ is applied before $\tau_{\sigma}$ is used in a meta-GGA functional from Libxc.