The physical mechanism of molecular alignment and orientation by a femtosecond two-color laser pulse Chaochao Qin, Yuzhu Liu, Xianzhou Zhang and Yufang Liu Eur. Phys. J. D, 68 5 (2014) 108 Published online: 07 May 2014 DOI: 10.1140/epjd/e2014-40658-9