%0 Journal Article %T From microscopic theory to macroscopic theory: a systematic study on static modeling for liquid crystals %A Jiequn Han %A Yi Luo %A Wei Wang %A Pingwen Zhang %J Mathematics %D 2013 %I arXiv %R 10.1007/s00205-014-0792-3 %X In this paper, we propose a systematic way of liquid crystal modeling to build connection between microscopic theory and macroscopic theory. A new Q-tensor theory based on Onsager's molecular theory which leads to liquid crystals with certain shape has been proposed. Making uniaxial assumption, we can recover the Oseen-Frank theory from the derived $Q$-tensor theory, and the Oseen-Frank model coefficients can be examined. In addition, the smectic-A phase can also be characterized by the derived macroscopic model. %U http://arxiv.org/abs/1305.4889v1