How to convert Ntfs index to lba?

Question

NTFS

A brief background: the disk is cut down in the form, but passes all Victoria tests (except seek, but it also often passes). Windows chkdsk does not work. Formatting and repartitioning does not help. The point is most likely in the mechanics and when referring to a certain place. I'm trying to localize, for a reasoned conversation with the guarantee. I know for sure that it turns off when checking file index entries under numbers in the region of 470,000+.
The question itself: in ntfs there are file index entries with numbers 470 000-500 000. How to determine their physical offset in lba? The disk is recently formatted, filled somewhere by 10%, the volume is 1TB, it was formatted by the 7th Windows.