about compatibility for gfortran

[gre88]

Dear Developers,

Thank you for your code! I have been using it for chemistry applications, it was great!
I have been using your code by customizing it for my purpose in the past using the fortran release. Since now g77 compiler has been discontinued, I would like to use gfortran to compile it. I think there might be issues with the cfftpack.f and chisqr.f libraries.
Is there any updated version that can be compiled with gfortran or some suggestion to compile the code with new compilers?

Thank you very much in advance