利用从头算Hartree-Fock方法和密度泛函理论方法,研究了1,3,5-苯三酸(苯三酸,TMA)和1,3,5-苯三酚(间苯三酚,THB)在高定向热解石墨(HOPG)上的增长过程.计算结果表明,两种分子的不同组装行为起源于氢键作用下的成核过程.TMA能够形成头碰头和非头碰头结构,从而形成两种不同的孔洞结构;THB只能形成非头碰头结构,从而形成密堆积结构.这些计算揭示了这两种结构相似的分子形成不同扫描隧道显微图像的微观机理. Using ab initio Hartree-Fock method and density functional theory, the effects of trimellitic acid (TMA) and 1,3,5-benzenetriol (phloroglucinol, THB) (HOPG). The calculated results show that the different assembly behaviors of the two molecules originate from the nucleation process under the hydrogen bonding. The TMA can form the head-to-head and non-head-to-head structure to form two Different pore structures are formed, and THB can only form non-head-to-head structures to form close-packed structures.These calculations reveal the microscopic mechanism of the formation of different scanning tunneling microscopic images by these two structurally similar molecules.