Zewdie, Habtamu (PhD)Awad, Mohamed2022-06-062023-11-092022-06-062023-11-091993-09http://etd.aau.edu.et/handle/12345678/31906The main objective of this work is to model a less computationaly demanding flexible single-site anisotropic potential using genera li zed spherical harmonic functions. These functions have been used to expand the well depth, f(r,u"w.), and the range, o(r,~"w2)' parameters of the s hifted Lennard- Jones (LJ) potential. We have compared our potential with si te-si te LJ and single- si te Gay-Berne (GB ) potentials. The results are in better agreement with LJ site-site potential for all tested orientations. The computational time is comparable to that of GB potential. The new potential has the additional advantage of f lex i bili ty. By taking addi tional spherical harmonic terms any desired accuracy can be obtained. this model is that it can also cylindrically symmetric molecules. The important virtues of be used to model noncylindrically symmetric molecules.enSingle-Site Anisotropic Pair Potential Based onThesis