tight-binding approximation meaning in English

紧束缚近似

Abstract : the effect of correction of self - consistent potential on electronic structure in simple cubic nanocrystal particles is calculated by means of the green ' s function method in the tight - binding approximation , taking only the nearest neighbor matrix elements into account . the numerical results show that the electronic energy spectrum is shifted , the chemical potential is not equal to the atomic energy level , the electronic density at each lattice point is changed , and the variation of electronic density at surface lattice point is the largest
文摘:在紧束缚近似下，只计及最近邻的矩阵元，采用格林函数计算了自洽势修正对简立方纳米晶体颗粒的电子结构的影响，发现电子能谱发生了移动，化学势不等于格点原子能级，各格点的电子密度也发生了变化，其中以表面格点的电子密度变化最大。
A perturbation method by tight - binding approximation which provide the relation of phase constant and angular spectrum of fields of in - waveguide is presented . the strip width of phase constant can be given . on the other hand , the group delay - time due to the k dispersion in single - mode transmission can also be estimated
提出一种利用紧束缚近似的微扰法计算阵列波导的相位常数与输入光角谱的关系，由此算出相位常数的带宽，并利用衍射方法估算单模传输中k色散引起的群延时。