 Determining a lossy parallel coil from its admittance

For series resistance R and inductance L in parallel with capacitance C, suppose the applied voltage amplitude V is fixed. The DC current gives $R=V/I_{\mathrm{DC}}$. If the high-frequency current is $I\sim \alpha \omega$, then $C=\alpha /V$. At the nonzero zero-phase frequency, current amplitude $I_r=VRC/L$ determines $L=VRC/I_r$. The condition $R^2<L/C$ must hold. The inferred zero-phase frequency is $\sqrt{1/(LC)-R^2/L^2}$; it is not automatically the exact frequency of minimum current magnitude.