Dear friend Rizwan Ur Rehman Sagar

One common method to theoretically calculate Raman peaks is using density functional perturbation theory (DFPT), which is a first-principles approach. However, if you are looking for a simpler method, there are several empirical methods that can give you an idea of the expected Raman peaks based on the material's structure.

One widely used empirical method is the bond polarizability model. This model assumes that the polarizability of a bond is proportional to its bond length and bond strength. Raman activity depends on the change in polarizability during the vibration, which can be calculated based on the vibrational mode symmetry. Several software packages are available that use this model to predict Raman spectra, such as Gaussian, VASP, and Materials Studio.

Another empirical method is the empirical force field (EFF) approach, which uses a classical mechanics-based approach to calculate the vibrational frequencies and intensities of molecular systems. This method is less accurate than DFPT, but it is faster and can be applied to larger systems. Some software packages that use EFF to calculate Raman spectra are MOPAC and CHARMM.

It is important to note that empirical methods may have limitations in predicting Raman spectra for complex materials, and the results should be taken with caution. It is always recommended to compare the theoretical predictions with experimental data to validate the method's accuracy.

Here are some references for Raman peak prediction software and tools:

1. Raman Spectrum Analysis: http://www.ramanspectrumanalysis.com/

2. Raman Spectrum Prediction Tool: https://spectrabase.com/rams_predictor.aspx

3. ChemSpider Raman Prediction Tool: http://www.chemspider.com/RamanPrediction.html

4. RAFAEL: Raman Active Frequencies for Ab Initio Electronic Structures: https://github.com/andrewtarzia/RAFAEL

5. PyFrag: a python program for fragment-based ab initio prediction of Raman spectra: https://pubs.rsc.org/en/content/articlelanding/2017/CP/C6CP08033C#!divAbstract

I hope you find these helpful!