Hello Ajit Kumar Kharwar.

What is the difference between them? The intensities don't match, or the pattern is shifted?... there are many possibilities of differences, and we can't find out the reason without seeing the differences.

Best regards,

Ricardo Tadeu

as Ricardo Tadeu Maia said the reasons of the absence of match can be different. If the positions of peaks are different maybe errors in the unit cell (space group, lattice parameters..) are present, while when the intensities are different the reasons could be due to the cell content or to preferred orientation in the powder. You should provide more details

As stated already - reasons can be different. Usually, SC-XRD is done at low temperature and there might be a difference in cell parameters between SC-XRD and XRPD measured at ambient temperature. I also encountered problems with solvation/desolvation where prepared single crystal did not represent the bulk as such - therefore slightly different XRPD. Or you picked one crystal for the measurement but the powder as such can be a mix of different crystallographic phases.. Providing XRPD patterns and data would be helpful.

I agree with @George E Kostakis and other scholars explanation for the discrepancy between both analysis, in which some masking of solvent and/or other disordered molecules decisions in the crystal lattice could be also additional factors.