D. Frenkel, Perspective on "The effect of shape on the interaction of colloidal particles" - Onsager L (1949) Ann NY Acad Sci 51 : 627, THEOR CH AC, 103(3-4), 2000, pp. 212-213
Onsager's paper on the effect of shape on the interaction of colloidal part
icles is seminal in many ways. I shall focus on two aspects: it is (to my k
nowledge) the earliest classical density functional theory, and it demonstr
ates the possibility of ordering transitions driven by entropy.