Abstract: A computer graphics system for modeling chemical molecules includes simultaneous two-dimensional and three-dimensional display of models of molecules from a single data set, and allows a user to edit in either two dimensions or three dimensions. A two-dimensional model may be stylized while a three-dimensional model of the same molecule remains chemically (geometrically) correct. The system has editing tools for use in both two dimensions and three dimensions, and changes made in one mode are immediately reflected in the other, and the editing tools include manipulation components for the user to display on elements of a model, and to use to move parts of a model of a molecule relative to other parts. The system includes techniques for structure determination and display that significantly reduce the computer power required to perform system functions, rendering techniques formally reserved to supercomputers usable on smaller computer platforms.