AC electrical measurements is an extension (in frequency domain) of the DC electrical measurements. AC electrical measurements may map the charges' transport (current) with common electrical elements (CEE) that we know from textbooks for DC/AC electrical circuits, i.e. we map the local charges' transport with CEE models. So, the parameters affecting current can be understood better, offering tools for material's optimization. For example, a piezoelectric quartz-crystal oscillator (PZT) has a simple direct model map between materials' or mechanical parameters of mass (m), spring constant (k) and energy losses (γ) with electrical equivalent model parameters of a coil (L), a capacitance (C) and a resistor(R) connected in series. This map is: m->L, k->1/C, γ->R. Thus, we may form a PZT-material's optimization process changing one (only) parameter in a well known RLC-model.