A computational Grid system with the simple architecture was constructed based on Globus and the concept of web application for the quantum chemical calculation. The computational Grid provides interfaces to a web-based input module and several molecular orbital calculation packages. Some aspects of the cluster modeling of the Ge(001) surface were tested on the constructed Grid. A number of conditions and parameters of the cluster model can be easily varied on the Grid, enabling concurrent testing of multiple choices of the model possible. These models were benchmarked on the Grid system. After that, the potential energy surface of the acetylene molecule moving over the model Ge(001) surface was scanned, in an effort to understand the adsorption reaction. Each point of the potential energy surface was calculated on the distributed node of the Grid system. These results demonstrate that the concept of high throughput computing can be successfully adapted to computational chemistry with a computational Grid. The result of modeling for the Ge surface itself is also described and could be of some interest.