accidently deleted macintosh HD data

Do you mean you erased the Macintosh HD - Data volume or that you deleted the volume in Disk Utility?

If the former, then the volume is still present. You can restore its content from your backup. However, if it's the latter, then you need to reinstall macOS. If you have no backup, then your data are gone, and you need to reinstall macOS.

Install macOS from Scratch

1. Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
2. Select Disk Utility from the Utility Menu and click on the Continue button.
3. When Disk Utility loads select the target drive (out-dented entry w/type and size info) from the Device list.
4. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
5. Set the partition scheme to GUID.
6. Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.)
7. Click on the Apply button, then wait for the Done button to activate and click on it.
8. Quit Disk Utility and return to the Utility Menu.
9. Select Install OS X and click on the Continue button.

You do have a Time Machine backup don't you? If you do not you are about to learn a painful lesson on why backing up is absolutely critical. If you have a back, simply restart in the Recovery Partition (Command + R on Startup) then restore from your Time Machine backup. If you do not have a backup, you system and all of its applications and data are gone. If you happen to use iCould for your data, you may have preserved some of that.

If you removed the volume, then you have to install macOS from scratch. If the volume is still there, but erased, then you can restore it from a backup if you have one. Otherwise, you will have to install macOS from scratch. To do that, please follow the instructions from me earlier post.