**6. Conclusions**

A numerical scheme for a new class of fractional diffusion equation was studied in this paper in which the time derivative was considered as the generalized fractional derivative. The scheme used the finite difference and collocation methods to find the numerical solution. The theoretical error and convergence analysis were also validated numerically. The numerical examples showed that the proposed method achieved high accuracy in comparison to other methods [34,36–38] presented recently.

**Author Contributions:** Conceptualization, S.K. (Sandeep Kumar) and R.K.P.; methodology, S.K. (Sandeep Kumar), K.K. and R.K.P.; software, S.K. (Sandeep Kumar) and R.K.P.; validation, S.K. (Sandeep Kumar), K.K. and R.K.P., writing—original draft preparation, S.K. (Sandeep Kumar), K.K., R.K.P., S.K. (Shyam Kamal) and T.N.D.; writing—review and editing, R.K.P., S.K. (Shyam Kamal) and T.N.D.; supervision, R.K.P.; funding acquisition, R.K.P., S.K. (Shyam Kamal), and T.N.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors sincerely thank the reviewers for their constructive comments to improve the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
