I am trying to generate a force field for a new molecule. I obtained bond foce constants but I don't know how to obtain angular force constants. Could you provide me a solution?
Use seminario's method to extract angular force constants. Its based on diagonalization of gaussian frequency matrices. you can simply use Hess2FF program for this kinds of calculations.
Link1: Article Systematic Derivation of AMBER Force Field Parameters Applic...
Link2: Article An automatic method to generate force-field parameters for h...