Your manual states that Chem3D can open a Gaussian checkpoint file. I have a Checkpoint file generated by Gaussian on my UNIX box, but Chem3D can't open it. I get the error message: "Sorry there are no atoms in this model." How can I view this file in Chem3D, so I can visualize the molecular orbitals?
The Chem3D 4 documentation is contadictory in its description of the types of Gaussian files that Chem3D 4 can open. The manual indicates that we can open Gaussian Checkpoint files with the .fchk and .fch extensions. This is a conflict, since Gaussian checkpoint files have a .chk extension and Formatted Checkpoint files have a .fchk or .fch extension. The manual should say that we can open Gaussian Formatted Checkpoint files, which are obviously different than checkpoint files. Chem3D 4 cannot open a checkpoint file (*.chk). So the solution is to create a formatted checkpoint file or a cube file, which you can then open in Chem3D 4.