Dear all,
I hope to use the gradient outputted by Tcl-ChemShell for further calculations. Below is my keyword.
list_option = full gradient = ${system_name}.grad
My question is that such 3N-dimensional gradient is calculated whether on cartesian or redundant internal coordinates.
Your help will be greatly appreciated.
Hi,
The gradient will be calculated and returned using Cartesian coordinates. It is possible to use other coordinate systems in the context of a geometry optimisation, but the actual calculations will always use Cartesians and be converted as necessary.
Best wishes,
Tom
Hi Tom,
Thank you for help! 
Best wishes,
Kalinite