Implementing of Gaussian Syntax-Analyzer Using ANTLR

The paper develops a Gaussian Syntax-analyzer using ANTLR. The Gaussian Syntax-analyzer is tested by an example, and builds the AST. Then we examine the analysis process of the example through parser tree generated by ANTLRWorks. The Gaussian Syntax-analyzer's design process is helpful for developing analyzer of other chemical software. At the same time, the paper also provides one kind of syntactical parser methods.