Crystal oscillators are loosely divided through the frequency they perform at and whether they are elementary oscillators—function for the frequency marked around the can or at even multiples of that (overtone oscillators). Modeling of nonlinear micromechanical resonators and their simulation With all the harmonic‐equilibrium method PDF 中原子或分子的排列具有三维空间的周期性，隔一定的... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html