The modelling of the diethynylsilane derivatives reveals large magnitudes of the first hyperpolarizability (β). The electron donor (D) and acceptor (A) groups are attached at both ends of the oligomers that containing up to ten heterocyclic rings. Several D/A pairs with different strengths were tested in this investigation. The magnitude of static and dynamic β was computed using the AM1/TDHF methodology. The presence of the alkyl donor groups containing heteroatom in the oligomers investigated contributes most for the largest values of the β hyperpolarizability observed. The effect of the oligomer chain length on the β magnitude is also investigated. The results demonstrate that the diethynylsilane derivatives are promising as second-order nonlinear optical materials.