伦敦分散力是彼此接近的两个原子或分子之间的弱分子间力。力是两个原子或分子彼此接近时电子云之间的电子排斥所产生的量子力。伦敦分散力是范德瓦尔斯力中最弱的，是当温度降低时导致非极性原子或分子凝结成液体或固体的力。即使它很弱，在三种范德华力（取向，归纳，分散）中，分散力通常占主导地位。例外是小的，易于极化的分子（例如水）。力量得名，因为Fritz London首先解释了1930年贵族气体原子如何相互吸引。他的解释是基于二阶扰动理论。又称：伦敦力，LDF，弥散力，瞬时偶极力，诱导偶极力。伦敦分散力有时可以被宽泛地称为范德瓦尔斯力。当你想到原子周围的电子时，你可能想象出微小的移动点，在原子核周围均匀分布。然而，电子总是处于运动状态，有时原子的一侧比另一侧的电子多。这发生在任何原子周围，但它在化合物中更为明显，因为电子感受到相邻原子质子的吸引力。可以布置来自两个原子的电子，使得它们产生临时（瞬时）电偶极子。即使极化是暂时的，它也足以影响原子和分子相互作用的方式。
英国布里斯托大学Assignment代写:伦敦分散力定义
London dispersion force is a weak intermolecular force between two atoms or molecules in close proximity to each other. The force is a quantum force generated by electron repulsion between the electron clouds of two atoms or molecules as they approach each other. The London dispersion force is the weakest of the van der Waals forces and is the force that causes nonpolar atoms or molecules to condense into liquids or solids as temperature is lowered. Even though it is weak, of the three van der Waals forces (orientation, induction, dispersion), the dispersion forces are usually dominant. The exception is for small, readily polarized molecules (e.g., water). The force gets its name because Fritz London first explained how noble gas atoms could be attracted to each other in 1930. His explanation was based on second-order perturbation theory. Also Known As: London forces, LDF, dispersion forces, instantaneous dipole forces, induced dipole forces. London dispersion forces may sometimes be loosely referred to as van der Waals forces. When you think of electrons around an atom, you probably picture tiny moving dots, spaced equally around the atomic nucleus. However, electrons are always in motion, and sometimes there are more on one side of an atom than on the other. This happens around any atom, but it’s more pronounced in compounds because electrons feel the attractive pull of the protons of neighboring atoms. The electrons from two atoms can be arranged such that they produce temporary (nstantaneous) electric dipoles. Even though the polarization is temporary, it’s enough to affect the way atoms and molecules interact with each other.