damping_fermi Function

public function damping_fermi(r, s_vdw, d, df, grad) result(f)

$$\begin{gathered} f_{(ij)}=\frac1{1+\exp\big({-}a(\eta-1)\big)},\qquad \eta=\frac{R_{(ij)}}{S_{\text{vdW}(ij)}}\equiv \frac{R_{(ij)}}{\beta R_{\text{vdW}(ij)}} \\ \frac{\mathrm df}{\mathrm dR_c}= \frac a{2+2\cosh\big(a(\eta-1)\big)}\frac{\mathrm d\eta}{\mathrm dR_c},\qquad \frac{\mathrm d\eta}{\mathrm dR_c}= \frac{R_c}{RS_\text{vdW}}- \frac{R}{S_\text{vdW}^2}\frac{\mathrm dS_\text{vdW}}{\mathrm dR_c} \end{gathered}$$

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=dp),	intent(in)			::	r(3)
real(kind=dp),	intent(in)			::	s_vdw
real(kind=dp),	intent(in)			::	d
type(grad_scalar_t),	intent(out),	optional		::	df
type(grad_request_t),	intent(in),	optional		::	grad

Return Value real(kind=dp)

Contents

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